Hey, we have a Dbacks contributor now! Welcome Matt O’Brien…
With 2021 firmly in the rear-view mirror and with the return of a full minor league season after a Covid induced hiatus, I thought now would be a good time to highlight some of the best performing and more intriguing prospects within the Diamondbacks’ farm system.
Mitchell Stumpo RHP
Mitchell Stumpo may not be a name many fans are familiar with. If you were to check out the top prospects on MLB.com he wouldn’t appear in the top 100. He doesn’t even make it into the Diamondbacks top 30. Yet fans may become a lot more familiar with the name over the course of the 2022 season.
The righty reliever was an undrafted signee in 2019 after struggling to post numbers for DIII Guildford College as a two-way player. In his first full season of professional baseball Stumpo has had a meteoric rise. He began the year at Low A Visalia where he was one of the oldest players in the league aged 24. He knew he had to make quick progress through the levels to make up for the age disparity and he did not disappoint. Stumpo spent a combined 6 weeks in Low and High A. He wound up spending most of his season at AA Amarillo where he posted an impressive 11.8 Strikeouts per 9 innings.
That is no mean feat for any prospect to accomplish. Especially when considering the hitter friendly nature of the leagues he had appeared in. It was, however, not the final stop for Stumpo after finally receiving the call to Triple A Reno on September 7th. Oh, and he also pitched in the Arizona Fall League for good measure, totalling 5 separate levels of competition in one year. Across all levels he managed to record a final ERA of 2.81 giving up only 6 home runs.
In an episode of Clubhouse Access on Arizona’s YouTube channel, farm director Josh Barfield described his progress as a “Cinderella story” and minor league catching co-ordinator Mark Reed stated, “He’s got a bright future, I think he’s going to pitch in the big leagues for a long time”. With a rise as rapid as Stumpo’s it is not beyond reason to think he may crack the big-league roster next year. Given his reputed “good fastball, really good cutter” and “nasty slider” he has the makings of being an effective shutdown reliever.
Alek Thomas OF
Alek Thomas will make his big-league debut in 2022, I am certain. How much of a role he will play remains to be seen. Thomas currently sits third in the organisation’s prospects list and is the 40th best prospect in all of baseball, per MLB.com.
The outfielder had an excellent 2021 campaign, moving up from Double A to Triple A in August after featuring in the prestigious Futures Game where he played against other top prospects such as Bobby Witt Jr. and Jasson Dominguez. Across the two levels Thomas posted a final slash line of .313/.394/559 with 18 home runs, 29 doubles and 12 triples. He bucked the trend by improving his offensive numbers after being promoted to Reno improving his OPS by almost .300. That may be partly down to the very hitter friendly nature of the Triple A West League. Thomas is blessed with electric speed and has proven he can handle all spots in the outfield. His bat to ball skill gets him on base regularly and there is more power to be tapped into once he matures.
Thomas may well be able to crack the opening day roster if he has a strong spring training although it may be worth starting him in Triple A to get regular at bats. After all, he has only had 34 games at that level.
Del Castillo could prove to be a steal for the Diamondbacks. The catcher had been tipped to go as high as 10th in some early 2021 mock drafts. He ended up slipping to the 2nd Round after he struggled to hit well for the University of Miami in his third year with the programme. Entering the year Del Castillo had been considered one of the best bats in the entire draft class. He earnt this after mashing over his first two college seasons where he posted an OPS of .995 and 1.025. He also walked more than he struck out.
The problems really presented themselves when the power dropped off in his third year. After posting successive years of .500+ SLG it fell to just .395. This became a worry when considered in conjunction with his defensive ability at catcher as Del Castillo may not be able to stick behind the plate long term.
There is hope for Del Castillo, however. Many would be hesitant to attribute too much reliance on a single season’s numbers, especially one that came after an interrupted campaign due to Covid. He spent much of his time after being drafted at Low A Visalia where he slashed .244/.341/.410 already seeing a small increase in his power output. Del Castillo is still relatively young, heading into his aged 23 season, and will have plenty of time to develop the bat. He might also be aided by the potential introduction of the universal DH in the new CBA, allowing him to focus purely on his hitting and maximising his offensive potential. If he can tap back into the power he showed early on, Arizona will be thankful they took the gamble when other teams passed.