Daniel Castano

The Marlins have designated left-hander Daniel Castano for assignment, tweets Daniel Alvarez Montes of El Extra Base (Twitter link). Castano’s spot on the roster will go to right-hander Johnny Cueto, whose previously reported one-year, $8.5MM contract has now been made official. Cueto was formally introduced this morning at Miami’s loanDepot Park.

Castano, 28, was one of four players the Marlins acquired in the heist that sent Marcell Ozuna to St. Louis, coming to Miami alongside Sandy Alcantara, Zac Gallen (since traded for Jazz Chisholm Jr.) and Magneuris Sierra. The left-hander has appeared in each of the past three seasons with the Marlins, logging a combined 3.89 ERA in 85 2/3 innings of work.

That solid ERA, however, has been accompanied by a 12% strikeout rate that ranks as the lowest of any pitcher in baseball dating back to 2020 (min. 80 innings). Castano has partially offset that lack of missed bats with a better-than-average 7.5% walk rate, a solid 44.7% ground-ball rate and a repeated knack for avoiding hard contact; his career 87.6 mph exit velocity, 7% barrel rate, 35.9% hard-hit rate (all as measured by Statcast) are each better than those of the average MLB hurler. Still, fielding-independent metrics like FIP (4.86) and SIERA (5.28) are more bearish on the left-hander than his more rudimentary ERA.

Castano’s 12.8% strikeout rate in the big leagues this past season was right in line with his career mark, but that’s a bit odd to see, given that he also overhauled his pitch mix and experienced a sharp uptick in strikeouts in Triple-A. Castano moved away from his four-seamer and sinker in favor of a cutter that he tossed at a hefty 41% clip. In Triple-A, the shift in his repertoire perhaps contributed to a career-best 26.4% strikeout rate. That wasn’t necessarily in a tiny sample, either; Castano’s 34 Triple-A frames were almost an exact match for his 35 2/3 Major League innings. It stands to reason, then, that even if Castano won’t see his MLB strikeout rate climb to quite those same heights, there’s perhaps reason to believe there’s more bat-missing ability in the tank than he’s shown in the Majors just yet.

Unfortunately for Castano, injuries robbed him of the chance to display more of that new-look cutter down the stretch. Castano landed on the shelf with a concussion in late July after being struck in the head by a 104 mph liner, and while he was working his back from that frightening scene, the Marlins discovered a small tear in his shoulder. He didn’t require surgery but also did not pitch again in 2022.

The Marlins will now have a week to trade Castano or attempt to pass him through outright waivers. He’s out of minor league options, so any team that acquires him will need to carry him on the roster or else try to pass Castano through waivers themselves. That said, he’s a lefty with a starter’s pedigree and some success in the upper minors, solid command and weak contact rates in the big leagues, and a somewhat intriguing new pitch that he began to lean on this past season. He can also be controlled for five more seasons. It’s certainly feasible that a pitching-needy club could place a claim or work out a small trade to acquire Castano.