Right-hander Declan Cronin will miss the 2026 season after undergoing Tommy John surgery two days ago, according to USA Today’s Bob Nightengale. Cronin spent much of the 2025 campaign with the Marlins but became a free agent after being released in September.
Injuries limited Cronin to just 23 1/3 minor league innings in 2025, without any action at the MLB level. He missed time in April and May due to a hip problem, and he didn’t pitch after August 16 after being placed on the injured list at Triple-A Jacksonville. The reason for Cronin’s placement wasn’t specified, but it is fair to assume that that injury led to his Tommy John procedure. UCL surgery makes for a pretty lousy birthday gift, as Cronin just turned 28 on September 24.
Cronin wasn’t designated for assignment prior to his release, so Miami simply cut him in order to clear a 40-man roster spot for Christian Roa’s contract selection. It is possible this transaction took place because the Marlins knew Cronin was facing or considering a major surgery, and so it wouldn’t be a surprise to see Cronin re-sign with Miami on something like a two-year minor league contract. This scenario would allow Cronin to spend a year rehabbing, and allow the Marlins some more roster flexibility this winter.
A 36th-round pick for the White Sox in the 2019 draft, Cronin made his big league debut by tossing 11 innings over nine appearances with the Sox in 2023. The following offseason saw him go from the Astros to the Marlins on a pair of waiver claims, and Cronin had a much longer stay in the Show when he posted a 4.35 ERA across 70 1/3 innings and 56 appearances out of Miami’s bullpen. His 3.28 SIERA was significantly lower than his ERA, as Cronin’s unwieldy .365 BABIP undid a lot of the promise shown by his secondary numbers (57.6% grounder rate, 23.5% strikeout rate, 8.2% walk rate).
Cronin is a grounder specialist, with groundball rates routinely in the high 50’s or over the 60% range during his minor league career. He kept the ball on the dirt much less frequently in 2025, which contributed to his 4.87 ERA over 20 1/3 innings in Jacksonville. With control also an issue both this season and at other various points in Cronin’s past career, it could be that the Marlins were just going to move on from Cronin entirely, regardless of his health situation. If a return to Miami isn’t in the cards, teams interested in his 2024 results might well consider a two-year minors contract as a rampway for Cronin to return to good health.
