This article is part of our Farm Futures series.
Predicting when a player like Cody Bellinger or Rafael Devers will be called up to make their big-league debut during the first five months of the season is an abstract activity that requires instincts, experience and a good feel for how a player's skills will play at the highest level. However, predicting which prospects and former prospects will be recalled when the calendar turns to September and rosters expand is more science than art.
In 90 percent of cases, a player's standing on the 40-man roster will open or shut the door on any conversation about a September callup. Very rarely does it make sense to add a player to the 40-man roster after Sept. 1. This is especially true of teams that are not contending.
There are three instances when a team will add a prospect to the 40-man roster in September. The first instance is when a contending team has a need and the only internal replacement is a prospect who is not on the 40-man roster. This is very rare, but it happened last year when the Red Sox promoted Yoan Moncada from Double-A in a desperate attempt to solve their problems at third base. The second scenario is when a team sees value in a player finishing out the minor-league season with a Triple-A or Double-A affiliate that is contending for a league title, and also sees value in that player joining the big-league club for the final weeks of the MLB season. Corey Seager's promotion two years ago is a recent example of both scenarios converging. The third scenario is when a player needs to be added to the 40-man roster in the upcoming offseason in order to be protected from the Rule 5 draft and the team is comfortable clearing a 40-man roster spot for that player prior to the offseason. This was the case when the Padres' selected Hunter Renfroe's contract last September.
What follows is an attempt to highlight the notable players who could be added to big-league rosters when rosters expand next month. They are sorted by the position they qualify for in fantasy, and within those positions they are ranked in order of how appealing they should be for fantasy owners looking to receive a boost over the final month of the season. Every player listed under a position is currently on their team's 40-man roster. The last two sections cover the players who will need to be added to their team's 40-man roster during the offseason for Rule 5 protection and those who are not on the 40-man roster and don't need to be added in the offseason.
CATCHER
Mitch Garver (Twins): Jason Castro and Chris Gimenez have been worth a combined 1.4 fWAR this season, so it's not like they have cemented their roles for the final month. Garver, 26, is old for a prospect, but a .291/.387/.541 slash line and 17 home runs in 372 plate appearances is impressive production for any minor-league catcher. Reports on his defense are promising, so he has a chance at carving out a role over the final month, and will be the favorite to break 2018 as the No. 2 catcher behind Castro.
Kevin Plawecki (Mets): Plawecki has benefited from regular playing time in the Pacific Coast League, posting a 127 wRC+ in 63 games -- his highest mark since he was at Double-A in 2014. Plenty of fantasy owners have been burned by Plawecki before, but Travis d'Arnaud has been terrible this year (0.3 fWAR), so it wouldn't be surprising if Plawecki were starting three days per week before the end of the season.
FIRST BASE/DH
Ronald Guzman (Rangers): Mike Napoli has no business being in a big-league lineup anymore and will be a free agent after this year, so Guzman should be given semi-regular playing time in September. His offensive profile is a little light for first base, and realistically he might produce like the pre-2017 version of Logan Morrison. Guzman is not a player to aggressively target this year, but hopefully we can learn a bit more about his skill set with a few weeks against big-league pitching.
A.J. Reed (Astros): We've all been here before. I would wager that Reed would be a better option than Carlos Beltran for the Astros over the season's final month, but I would also wager that the Astros won't give him a legitimate shot at earning steady at-bats. Still, it will be worth keeping an eye on. He has the approach and raw power to be useful if he is getting at-bats.
Kennys Vargas (Twins): It says a lot about Vargas' shortcomings that he was unable to wrangle the starting DH job away from Robbie Grossman earlier this year. I can't even point to some amazing numbers with Triple-A Rochester that suggest something will be different this time around. What I can tell you is he has light-tower power and is one of the few people I'll mention in this article who could hit six or seven homers in a month.
Renato Nunez (A's): Oakland's Triple-A roster and big-league roster aren't all that different in terms of talent, so there are roughly a dozen guys at Nashville who could get a look in September. Nunez has the most power potential of that group (31 HR in 112 games), but might only get to play against lefties.
Daniel Vogelbach (Mariners): The nice thing about September is that Vogelbach will HAVE to be summoned. Of course, he probably still won't get much of a look, but it's possible that he could produce in a couple of random starts and then parlay that success into a bigger role. Like most of the hitters in the first base/DH group, he has nothing left to prove at Triple-A.
Tyler Austin (Yankees): Austin is probably a Quadruple-A hitter, but the Yankees are starting Chase Headley and his .129 ISO at first base, so it would stand to reason that he will be able to get a start or two per week. If he gets hot, he could ride that to regular work.
SECOND BASE
Raul Mondesi (Royals): Mondesi's struggles in the big leagues thus far may result in him seeing almost no playing time when he gets the call. Of course, he is not guaranteed even one start per week, but Alcides Escobar has been so bad this year and Mondesi has been so good at Triple-A (121 wRC+, elite defense at shortstop), that he could work his way into the mix. Mondesi is much more exciting in dynasty and keeper formats, as he will be the Royals' everyday shortstop in 2018, and offers the potential for 10-to-15 home runs and 30-plus steals. There will likely still be some growing pains with strikeouts/AVG/OBP, but the speed alone should make him playable in standard leagues. Despite just turning 22, he is no longer prospect eligible, but if he were, he would be a borderline top 30 prospect.
Ryan Schimpf (Padres): My Trevor Story comp of Ryan Schimpf in Coors Field looks better by the day. Schimpf is pretty awful, relative to other big-league second basemen, but for fantasy owners who need home runs and can withstand a batting average hit over the span of 60-to-80 plate appearances, Schimpf could deliver.
THIRD BASE
Jeimer Candelario (Tigers): The Tigers should be able to mix and match enough to get Candelario at least a dozen starts in September. It seems like he has sacrificed batting average to get to a bit more power this year, but hitting for impact power in Comerica Park will still prove challenging. His lack of major upside and unpredictable usage will make him a tough player to extract fantasy value out of over the final month.
Miguel Andujar (Yankees): He will likely need an injury to get even a start or two per week, but Andujar is a top 200 prospect and will be up in September, so that's worth noting. The 22-year-old has a 142 wRC+ in 41 games at Triple-A, and could force his way into the mix next year.
Yandy Diaz (Indians): He's too old (26) and probably won't hit for enough power, but I just can't get over his approach (53:58 K:BB in 353 plate appearances). He can play both corner outfield spots and third base, so hopefully he gets enough playing time in September for us to get a better sense of what his fantasy upside could be with regular at-bats in 2018.
Jurickson Profar (Rangers): It's kind of sad to think about the way we talked about Profar five years ago and the way we talk about him now. It's worth pointing out that he is still just 24 and has more walks (34) than strikeouts (26) while slashing .304/.391/.459 in 74 games at Triple-A this year, primarily playing shortstop. Unfortunately there is really nowhere for him to play at the big-league level, as his bat probably can't handle a corner. Regardless, he'll be up in September.
SHORTSTOP
Franklin Barreto (A's): Barreto is only 21 and he has more speed than he's shown at Triple-A, but I still think this has been a pretty disappointing year for him. He hadn't been worse than 17 percent above league average at any stop above rookie ball, and then he goes to the Pacific Coast League and posts a 91 wRC+ with a 28.6 percent strikeout rate, which is easily his worst rate in the minors. He also looked completely overmatched in the big leagues in a brief cup of coffee earlier this year. Barreto will be up in September, but I don't expect him to play a ton. He is worth a dart for owners looking for cheap speed and some upside at middle infielder.
Willy Adames (Rays): I've had people ask why they should like Adames as much as I do (No. 18 overall on the top 400), and I get why people might not be wowed by his numbers at Triple-A. First, consider that he won't turn 22 until September. Then check out his approach (111:61 K:BB in 495 plate appearances) and factor in that he will grow into much more game power than he is currently showing. He is incredibly muscular by shortstop standards. If it weren't for the Coors Field factor, I would actually have Adames ranked ahead of Brendan Rodgers. He's legit. Now, he may not even get a call in September despite being on the 40-man roster, as the Rays are very cost-conscious and could opt to wait until April or May of 2018 to promote him. However, Brad Miller has been really bad this year, and Adames may represent an upgrade.
OUTFIELD
Stephen Piscotty (Cardinals): This is an obvious one, but Piscotty is hitting .304 with four home runs in six games since getting demoted to Triple-A. He is not a star, but the Cardinals need to find room for him.
Jorge Soler (Royals): The Royals simply haven't needed Soler this year, otherwise he would have been up a while ago. Well, technically they would have been better if Soler had taken all of Alex Gordon's at-bats, but Gordon is owed another $40 million over the next two seasons, so they aren't going to bench him now. Soler could get some starts at DH and occasionally right field when he gets the call in September, and if he can pick up where he left off at Triple-A (147 wRC+), he could parlay those starts into everyday work down the stretch.
Raimel Tapia (Rockies): Perhaps no player on this list (non-Piscotty division) has mastered Triple-A to the extent Tapia has (140 wRC+). Unfortunately he has had a hard time getting consistent playing time when he has been up in the big leagues because the Rockies are contending and they have three veteran outfielders ahead of him on the depth chart. If someone were to get injured ahead of him, he would be a good option for speed and a high batting average over the final month.
Jordan Luplow (Pirates): Luplow is hitting .419 with two home runs and one steal in 12 games since being sent back to Triple-A Indianapolis, and with Gregory Polanco (hamstring) out indefinitely, there could be an opportunity for Luplow to earn legitimate playing time. He doesn't carry the same name value as Austin Meadows, but there is no denying who is more deserving of a shot in 2017.
Tyler Naquin (Indians): From Rookie of the Year candidate last year to organizational depth this year. To Naquin's credit, he has raked at Triple-A (.311/.369/.504), but the Indians obviously don't care for his outfield defense. If manager Terry Francona wants to favor offense over defense against a righty, Naquin would be an obvious option over Austin Jackson in the season's final month.
Brett Phillips (Brewers): Lewis Brinson would appear much higher on this list if he had not suffered a significant hamstring strain that could keep him out through the end of the regular season. That injury makes Phillips somewhat interesting, as Ryan Braun is always at risk of missing a week or two with a nagging injury, and Keon Broxton is slump prone. The most likely scenario is that Phillips just gets the occasional start against a lefty. He profiles as a high-end fourth outfielder long term.
Mark Zagunis (Cubs): Zagunis was just placed on the minor-league DL with an undisclosed injury, but if it is a minor injury, he will be up with the Cubs in September. The Cubs already have a pretty crowded outfield, but Zagunis mashes lefties and could form a platoon with Kyle Schwarber in left field if the Cubs are willing to sacrifice defense for offense.
Teoscar Hernandez (Blue Jays): He will join the Blue Jays in September, but Hernandez may struggle to get playing time, as his greatest strength (mashing lefties) is also Steve Pearce's greatest strength. Hernandez will be given a chance to earn everyday at-bats in 2018, and he could offer cheap power and speed if that happens, with a middling batting average and solid on-base skills. However, the more likely outcome is that he is relegated to the short side of a platoon.
Franchy Cordero (Padres): The Padres have a few Triple-A outfielders who will probably get the call in September, but Cordero is the one who has the best chance of getting hot and contributing some power and speed over the final month. Like most of the players at this point on the list, Cordero is likely a fourth outfielder long term, and he may not even hit enough to succeed in that role. He has above-average raw power and average speed, and Jose Pirela has to cool off at some point.
Tony Kemp (Astros): I've always loved Kemp, and it's really quite a shame that he had to come up in an organization where he is seemingly blocked at every turn. His natural position is second base, but barring an injury to Jose Altuve, Kemp's only avenue to playing time will be in left field. He is a plus runner and has tapped into some PCL-aided pop this year. He also rarely strikes out (8.2 percent strikeout rate). Unfortunately, given the Astros' depth, he will likely only see a few starts in September, but he's someone to watch if he ever gets dealt or Altuve ever suffers a serious injury.
STARTING PITCHER
Tyler Glasnow (Pirates): Of the pitchers mentioned in this article, Glasnow should be the most widely owned. He has done everything in his power at Triple-A to re-establish intrigue in his immense potential, despite sporting a 6.49 ERA in 77.2 MLB innings. His 9.7 percent walk rate with Indianapolis, while still high, is his lowest mark since he was at Double-A in 2015. Fringe-average fastball command could still be his undoing when given a chance in September, but there is also extreme upside if he can put it all together for a month.
Luke Weaver (Cardinals): Weaver just needs a spot in the rotation. With expanded rosters, the Cardinals will have the luxury to go with a six-man rotation here and there, while also skipping another starter's turn if they deem it prudent. He should be useful in all formats on a per-start basis, we just don't know how and when he will get those starts.
Brock Stewart (Dodgers): Stewart is a poor man's Weaver, in that we know he can be useful on a per-start basis, especially in deeper leagues, it's just unclear how he will get big-league starts over the season's final month. The Dodgers have such a massive cushion (13.5 games up on the Nationals), they could start resting some of their top starters over the final month, using guys like Stewart to eat innings and keep their top pitchers fresh for the postseason. It may be tough to utilize Stewart in leagues with weekly lineups, as we may not know well in advance when he will get the ball, but he certainly figures to get a few starts in September, one way or another.
Lucas Giolito (White Sox): The White Sox have kept Giolito in the minors all season because he has not been deserving of a promotion. Once the minor-league season ends, however, it probably makes more sense to see how he does against big-league hitters, rather than continue to give Derek Holland starts. Don't expect positive fantasy contributions, but he did post a 24.3 percent strikeout rate this year, so there is some upside for those desperate for September production.
Domingo German (Yankees): If the Yankees need to fill a starting vacancy via someone on the 40-man roster, German is the most qualified candidate. He sports a mid-90s fastball with decent secondary stuff, and while some question his ability to hold up as a starter long term, he's healthy and pitching well at Triple-A.
Buck Farmer (Tigers): Farmer has a 6.62 ERA and 3.42 xFIP in four big-league starts this year, as he missed bats (22 strikeouts in 17.2 innings) but gave up the long ball with regularity (2.55 HR/9). He also has a 3.31 FIP at Triple-A, so there's a hint of potential if he were to get starts in the final month, but there is probably too much risk to take a shot on him in standard mixed leagues.
Junior Guerra (Brewers): Guerra is extremely volatile, so he could be excellent in a couple September starts, or he could completely sink a fantasy team's ratios. He won't see any starts without an injury to someone in the Brewers' rotation, but Guerra does seem like the next man up.
Steven Brault (Pirates): After Glasnow, the Pirates have several other starters at Triple-A who are on the 40-man roster and deserve a look in the big-league rotation. With apologies to Nick Kingham and Clay Holmes, Brault would probably be the next guy to get a shot. A command/control lefty, Brault has a 1.94 ERA at Triple-A, but has not yet been able to show he can consistently get big-league hitters out.
Brian Johnson (Red Sox): If the Red Sox want to start aligning their rotation for the postseason or skip a starter here or there, or they grow tired of Doug Fister, Johnson would be the arm they would likely turn to. His strikeout totals at Triple-A leave a lot to be desired, but he could be serviceable in deeper leagues.
Erick Fedde (Nationals): Fedde's prospect stock has taken a hit this year. His strikeouts are down, he was experimented with as a reliever, and he bombed in two big-league starts this season. Still, he carries some name value and would conceivably be next up if the Nationals need to dip into their starting pitching depth.
OFFSEASON 40-MAN ADDS
Brent Honeywell (Rays): Honeywell would have been inserted into the big-league rotation a month ago in many organizations, but the Rays' slow-cooking player development style is on display once again. He is at 125 innings for 2017 after getting to 115.1 innings in 2016, so it's unclear exactly how much he has left in the tank. Honeywell would be devastating as a multi-inning reliever, so the Rays have options for how to best use him over the final month. Those who have been stashing him may as well continue to hold out hope that he gets starts, but I'd bet on him being deployed out of the bullpen in September.
J.P. Crawford (Phillies): Crawford is slashing .293/.383/.561 with seven home runs in 32 games since the All-Star break. While it is a little surprising that he will be the last of the Rhys Hoskins/Nick Williams/Jorge Alfaro/Roman Quinn crop of prospects to reach the big leagues, Crawford has finally earned a look. The question is whether the Phillies value giving him a month's worth of big-league at-bats over gaining an extra year of control by waiting until mid-April to call him up next year. I think it's a coin flip. If he does get the call, I expect him to play almost every day.
Stephen Gonsalves (Twins): Gonsalves may get the call before September, so now is the time to take a flier on him. He relies more on deception than explosive stuff, but so far that approach has allowed him to dominate at every level of the minors. It would be a little odd to see the Twins promote a top prospect after just a few starts at Triple-A, but his polish and their need may converge to make it happen.
Tyler Mahle (Reds): Mahle is the rare Reds pitching prospect with above average command, and he represents an upgrade over at least two or three of the current members of the big-league rotation. He has plenty of innings left this season, and the Reds have some expendable pieces on the 40-man roster, so I'll bet on him getting added to the rotation for the season's final month. Mahle doesn't offer a ton of strikeout potential, but he could still be serviceable in deeper leagues. I like him as a sleeper for 2018.
Brian Anderson (Marlins): Not all 40-man roster spots carry the same value. The Marlins can easily make room for Anderson, who is probably the best healthy third baseman in the organization. He has murdered Triple-A pitching so far (165 wRC+) and could stay hot over a month with the big-league club if they are willing to give him a shot. Anderson's lack of name value should make him easily acquirable, even after a promotion is official.
Austin Meadows (Pirates): This has amounted to a lost year for Meadows, as his hamstring issues once again cost him developmental time, and he performed poorly when on the field. The Pirates have a lot to figure out this offseason regarding the outfield, but in the short term, it's hard to argue Meadows would give them a boost if added in September. Jordan Luplow is the Pirates outfielder to monitor over the final month.
Luiz Gohara (Braves): Gohara started the year at High-A, and is now knocking on the door of the big leagues. He has already logged 40 more innings than he did last season, so the Braves may opt to just shut him down after the minor-league season. Either way, he should compete for a spot in the Opening Day rotation in spring training next year, as he will need to be added to the 40-man roster this offseason.
NON-40-MAN CANDIDATES
Chance Adams (Yankees): I've been waiting for Adams to get a shot in the Yankees' rotation for over a month, and while the additions of Sonny Gray and Jaime Garcia did nothing to expedite that process, the injuries to Michael Pineda and Masahiro Tanaka may have cracked that door open a little. Adams has a 2.56 ERA and 1.01 WHIP at Triple-A with legitimate mid-rotation stuff, so if he gets the call, he should be added in all formats.
Wilmer Font (Dodgers): The Dodgers don't have explicit needs anywhere, so it's hard to know what their stance will be regarding adding someone like Font to the 40-man roster. Unlike with Alex Verdugo, I doubt the Dodgers will be worried about losing a year of control over Font by promoting him this year, but they also won't jump to clear a 40-man roster spot just because Font has had a good year at Triple-A. Font leads all minor leaguers with 168 strikeouts in 125.1 innings, so he is well worth an add in all formats if it becomes clear that he will make big-league starts in September.
Rogelio Armenteros (Astros): If the Astros are willing to go outside the 40-man roster for a starting pitcher in September, Armenteros is the most deserving of that shot. His stuff is not as overpowering as his minor-league strikeout totals suggest, but he could be a solid No. 4 starter, and on the Astros, that could lead to double-digit wins over a full season. At the very least, he has pitched himself into the mix for a rotation spot at some point in 2018.
Willie Calhoun (Rangers): Everyone seems to think Calhoun will be up at some point this year, now that he plays for an American League team. Like the rest of the players in this group, he is not on the 40-man roster and does not need to be added during the offseason. Unlike the rest of the players in this group, he does not play for a contender. It is extremely rare for a player who doesn't check any of those three boxes to get the call in September, so I'm betting against Calhoun debuting in 2017. If he does, then he's a must add in deeper mixers, as the bat is absolutely ready to do some damage against big-league pitching.
Alex Verdugo (Dodgers): Verdugo is ready for the big leagues and he plays for a contender. However, the Dodgers don't have a need in the outfield, and he is not on the 40-man roster, so this is a tough one to forecast. It may sound strange, given the hype surrounding Verdugo and comments from the front office suggesting he is ready for the big leagues, but I'm going to bet against him getting added to the 40-man roster after the minor-league season. Any marginal upgrade he might give them probably isn't worth losing a year of control long term. Look for him to get the call in mid-April 2018.
Walker Buehler (Dodgers): Buehler will receive plenty of hype for single-season leagues next year, but considering he has already been moved into a relief role at Triple-A, he won't be making any big-league starts this year, even if he is added to the 40-man roster.
