This article is part of our Minor League Barometer series.
The injury to Vladimir Guerrero, Jr. certainly puts a damper on those that expected the "Summer of Vlad" to be in full bloom by the All-Star Break. Instead, the younger Guerrero will be reevaluated in a month due to a strained left patella tendon, and the non-contending Blue Jays will almost certainly exercise extreme caution with arguably the top prospect in all of baseball.
Which players are on the rise, and which players have seen their stock take a nosedive? Let's find out in this edition of the Minor League Barometer.
Chris Paddack, P, SD – Paddack's return from Tommy John surgery has been nothing short of spectacular. The 22-year-old righty has picked up right where he left off in 2016, striking out the opposition with reckless abandon. Paddack has an astounding 70 strikeouts in just 42.1 innings at High-A Lake Elsinore. Perhaps even more impressive, Paddack has issued just three walks over that span. Yes, you read that correctly. Paddack boasts a 1.91 ERA, has fanned at least seven hitters in every start this season, and has not allowed an earned run in five of those eight outings. Paddack's dominance, particularly, in the hitter-friendly confines of the California League, has boosted him near the top of the list of all pitching phenoms in the minors.
Kevin Smith, SS, TOR – Smith is going to have to contend with Bo Bichette being in front of him in the pecking order, but, that has not seemed to bother the less-hyped shortstop to begin the 2018 campaign. In fact, the 21-year-old Smith has been nothing short of sensational. He slashed .355/.407/.639 with seven home runs, 44 RBI and 12 steals in 46 games at Low-A Lansing. The fourth round pick out of Maryland received a quick promotion and has continued to rake at High-A Dunedin. Smith is hitting .339/.391/.516 with three home runs and nine RBI in 14 games since being promoted. Smith has vaulted up the prospect charts with this hot start, showing power, speed and the ability to hit for both average and power. He may end up needing a trade to play every day in the big leagues, but Smith is proving he can hit after largely being considered a "glove-first" player when drafted out of college.
Forrest Whitley, P, HOU – As if the Astros don't have enough starting pitching at the big-league level, Whitley returned from a 50-game suspension for recreational drug use and hurled four scoreless innings for Double-A Corpus Christi. He followed that outing up with four more scores innings last week. Whitley could have the most upside of any pitcher in the minors, and due to the suspension, he should not be limited in terms of innings for the remainder of the season. That could even allow the Astros to bring him up later in the summer. Whitley is advanced for his age, has four pitches that he can throw for strikes, and is a presence on the mound at 6-foot-7. He is the real deal.
Luis Rengifo, SS, LAA – Traded from the Rays to the Angels right before the season, Rengifo has come from virtual anonymity to become one of the fastest risers in the minors in 2018. The toolsy middle infielder did have 12 home runs and 34 steals at Low-A last year, but he hit .250 and saw an increase in strikeouts. Rengifo's stellar plate discipline has returned in 2018, though, as he has more walks (35) than strikeouts (30) in 63 games across two levels. He is currently hitting .330/.404/.568 with two home runs, 15 RBI and six steals through 22 games for Double-A Mobile. Speed is Rengifo's best asset, but he also has some pop, and if he can hit for average at the higher levels, he will become an extremely coveted middle infield prospect.
Brendan Rodgers, SS, COL – The closer Rodgers gets to the big leagues, the closer the Rockies get to having to make a decision. Rodgers is hitting .291/.343/.549 with 14 home runs, 50 RBI and nine steals in 65 games for Double-A Hartford. Rodgers has already exceeded his career high in steals, and he's on pace to shatter his previous career best in home runs. Rodgers should be the shortstop of the future, right? Well, Trevor Story is having a superb season at the big-league level. He is hitting .270 with 15 home runs, 54 RBI and nine steals. He actually leads the National League in RBI. With D.J. LeMahieu at second and Nolan Arenado at third, Rodgers would appear to be blocked despite all the tools and pedigree. As a result, Rodgers may be forced to send additional time in the minors despite the fact that he may already be close to MLB-ready.
Dane Dunning, P, CHW – Dunning was the least talked about pitching prospect in the Adam Eaton deal near the end of the 2016, but he has continued to shine since coming over from the Nationals. His last start for Double-A Binghamton was a dandy, as the 23-year-old righty tossed eight scoreless innings, scatted four hits, did not walk a batter but struck out 10. Across two levels in 2018, Dunning has a 2.72 ERA and 96:22 K:BB in 82.2 innings. Dunning gets ground balls and has impeccable command. He does not have the pure stuff of fellow White Sox pitching prospect Michael Kopech, but Dunning is more polished at this time.
Jonathan Loaisiga, P, NYY – With all the chatter about Justus Sheffield and Chance Adams, among others, the 23-year-old Loaisiga can easily be overlooked in terms of organizational depth. However, the Yankees have taken notice of the Nicaraguan righty, who has been dominant thus far in 2018. In fact, the Bronx Bombers called up Loaisiga, and not the aforementioned Sheffield or Adams, to start last Friday versus the Rays and take the spot of the injured Masahiro Tanaka. He responded with five shutout innings, fanning six batters in the process. He was a bit wild, though, walking four batters over that span. Still, nerves can be blamed for that, as he had just 24 walks in his entire minor league career, a span of 148.2 innings. Loaisiga will get a couple more starts before Tanaka returns, but if he impresses, the Yankees will be hard pressed not to keep him in the rotation.
David Peterson, P, NYM – How about some good news for the Mets? Peterson found little resistance at Low-A to begin the 2018 campaign. In nine starts, the first round selection from the 2017 draft posted a 1.82 ERA and 57:11 K:BB, a span of 59.1 innings. Despite big frame (6-foot-6, 240-lbs), Peterson does not throw exceptionally hard (topping out around 93 mph), but his slider is superb and he is usually in and around the zone with his deceptive, long delivery. Peterson's first start at High-A was mediocre, but the 22-year-old southpaw and University of Florida product should be able to adjust quickly to this level, and perhaps even see Double-A by the end of the season.
Austin Riley, 3B, ATL – A sprained posterior cruciate ligament in Riley's right knee has landed him on the Disabled List at Triple-A Gwinnett, and he may be sidelined through the end of the month. Depending on his recovery, this injury could cost Riley a chance at taking over the third base job sooner rather than later for the big club. Johan Camargo is hitting just .221 at the hot corner, while Ryan Flaherty has come crashing down to earth since a hot start. The Jose Bautista experiment failed as well. The 21-year-old Riley has power and is the future at third for the Braves, but he's battled plate discipline concerns in the recent past. Still, a healthy Riley will likely take over at third base for the Braves by August, but it could have been sooner if not for the injury.
Jon Duplantier, P, ARI – Arguably the top prospect in the Arizona organization, Duplantier has been battling biceps tendinitis and has not made a start for Double-A Jackson since the end of May. While this particularly injury is not considered serious, it is worth noting because Duplantier has a history of elbow and shoulder problems. As a result, the Diamondbacks may proceed cautiously with the top arm in their system. When on the mound, Duplantier has been incredible, posting a lifetime 1.62 ERA and 209:55 K:BB in 172.2 innings in the minors. However, even the most dominant athletes can be betrayed by their bodies. Duplantier will need to prove he can stay on the field and be productive as well at the higher levels.
Hunter Harvey, P, BAL – At one time considered the top prospect in the Baltimore organization, Harvey's professional career has been marred by injury. Already the recipient of Tommy John surgery, Harvey had his right shoulder pop out of its socket at the beginning of June and has not pitched since then due to soreness. Harvey wasn't exactly dominating even prior to the injury, sporting a bloated 5.57 ERA in 32.1 innings. Harvey's questionable durability and checkered injury past has knocked him swiftly down the prospect rankings in recent years. Though he does have a 30:9 K:BB in those 32.1 innings at Double-A Bowie, he has never pitched more than 87.2 innings in a single minor league season, and it remains to be seen if his arm will be able to withstand the rigors of a full MLB season.
Stephen Gonsalves, P, MIN – The 23-year-old southpaw has hit a bit of a wall at Triple-A after finding very little difficulty at the lower levels of the minors. Gonsalves had a 5.56 ERA in five outings last year at Triple-A. In nine starts at Triple-A in 2018, Gonsalves has a 5.10 ERA. Gonsalves has been issuing far too many walks; he has 28 free passes in 42.1 innings at Triple-A thus far this season. Though the opposition is hitting just .206 against him, and he does have 46 strikeouts over those 42.1 innings, it is clear that the added base runners from the walks have caused the high ERA. Fellow Twins hurler Fernando Romero may have passed Gonsalves on the depth chart with his recent run in the big leagues as well, while Gonsalves is left to find his control at Triple-A.