What Went Wrong With the Marlins’ A.J. Puk Experiment?

Although he has flashed starter potential, a full-time role in the bullpen is likely what's best for Marlins pitcher A.J. Puk.

Miami Marlins pitching coach Mel Stottlemyre Jr. speaks with pitcher A.J. Puk (35) during the second inning of an MLB game on opening day against the Los Angeles Angels at LoanDepot Park.
Miami Marlins pitching coach Mel Stottlemyre Jr. speaks with pitcher A.J. Puk (35) during the second inning of an MLB game on opening day against the Los Angeles Angels at LoanDepot Park in Miami, Florida, on Wednesday, April 3, 2024. (D.A. Varela/Miami Herald/Tribune News Service via Getty Images)

Coming out of the University of Florida back in 2016, A.J. Puk looked to have all of the tools to make him a potential front-of-the-line starter. Even more so when the Oakland Athletics selected him sixth overall in the draft.

Yet, those days seem to be long gone now that he has been unable to stick in a big league rotation with two different organizations.

Oakland was willing to give Puk every opportunity possible in hopes that he would regain his college form and fill a rotation spot for them. However, after a slew of injury setbacks during his development process, Puk’s future seemed to be in the bullpen at the MLB level.

The A’s eventually decided to move on from Puk when they traded him to the Miami Marlins during the 2022-23 offseason. The deal was a one-for-one swap for JJ Bleday that mirrored a similar trade they made at the 2021 deadline involving Starling Marte and Jesús Luzardo.

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A.J. Puk entered spring training this season looking to be a lockdown back-end reliever after a strong 2023. However, with the Marlins trying to piece together a five-man rotation after dealing with injuries to multiple starters, they decided to make Puk a starting pitcher again coming into the 2024 campaign.

If we went back in time to right before the regular season started and only looked at Puk’s numbers from the spring, you would have deducted that the experiment was working out in the Marlins’ favor.

In four starts during spring training, Puk pitched to a 1.32 ERA across 13.2 innings. In those innings, he also piled up 23 strikeouts while limiting the free passes to only four. Master Mel looked to have done it again!

Puk’s regular season, however, did not end up starting strong.

Before landing on the injured list with left shoulder fatigue, Puk looked to have lost his feel for the strike zone. In four starts, he issued 17 walks in only 15 innings of work. He also allowed opponents to hit at a .306 clip, posting a 2.40 WHIP. He had trouble throwing any pitches for strikes, barely hovering over the 50% mark in strikes thrown.

Although Puk does have starting pitching experience, it is a different beast once you reach the professional level.

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The physical, and mental, demands of starting pitching can put the body under a lot more stress than the challenges of shorter outings. Building up to be able to withstand so many up-downs, high pitch counts, and the overall conditioning of the body is not something that every pitcher is able to do.

While I do not want to bury any professional baseball player’s potential in their career, it also seems as if multiple arm injuries have been a detriment to Puk’s ability to build back up to a full-time starting role.

Just in his MLB career alone, he has sustained the following injuries:

Aside from those injuries, Puk also missed all of the 2018 and ’19 seasons after undergoing Tommy John surgery. His 2020 shoulder injury was also one that caused him to miss the entire season after a lingering issue turned into something that had to be surgically repaired.

While A.J. Puk has shown flashes of starting potential in his career, a future in the bullpen is likely what is best for him going forward.