Mariners right-hander Luis Castillo has received plenty of interest from various clubs amid a hot market for starting pitching this winter, with the Red Sox and Cubs among the teams who have been connected to the right-hander so far. A report from The Athletic’s Ken Rosenthal this evening name-checks two more clubs who have “at least inquired” after the veteran: the Mets and the Orioles. With that said, however, Rosenthal emphasizes that Mariners are only willing to deal Castillo if the return package improves the big league club as they look to return to the postseason next year.
Both clubs are certainly sensible suitors for the right-hander. The Mets have already added Clay Holmes and Frankie Montas to a rotation that entered the offseason with only Kodai Senga and David Peterson locked into starting roles for 2025, but those additions offer little certainty to the Mets. That makes a steady and reliable arm like Castillo’s a sensible choice for that final rotation spot in Queens, but it’s unclear whether New York has the big-league ready pieces to offer Seattle in order to facilitate a deal. Top prospect Luisangel Acuna would surely be attractive to the Mariners as a big league ready infield option who looked good in a 14-game cup of coffee with the Mets last year, but the soon-to-be 23 year old could be a major factor in the club’s plans for 2025 given his ability to not only play the infield and also a strong center field. That figures to be particularly true if the Mets fail to re-sign Pete Alonso and move Mark Vientos to first base, which would seemingly open up regular playing time for Acuna at either second or third base.
The Orioles, by contrast, have a surplus of talent around the infield that could be attractive to the Mariners as they look for a front-of-the-rotation arm to replace free agent hurler Corbin Burnes. In particular, the club has a bit of a logjam at first base that the Mariners could stand to benefit from. While it’s unclear if Baltimore would be willing to part ways with top prospect Coby Mayo, Ryan Mountcastle and Ryan O’Hearn were forced to share first base duties last year thanks to a crowded positional mix that figures to only become more cramped with the growing playing time needs of youngsters like Mayo, Heston Kjerstad, and Jackson Holliday. With Holliday poised to take over second base on an everyday basis in 2025, it’s also possible that a veteran infielder like Ramon Urias could be available for the Mariners in a deal.
Another obstacle to a potential Castillo deal, Rosenthal writes, is that parting ways with the right-hander could leave the club thin on rotation depth. While their top four of Logan Gilbert, George Kirby, Bryce Miller, and Bryan Woo would remain among the strongest in the sport, big league ready options like Emerson Hancock and Jhonathan Diaz don’t provide much confidence for the Mariners’ back-end. One solution to that problem, of course, could be a young pitcher heading back to Seattle as part of the return for Castillo. The Cubs (Jordan Wicks and Javier Assad), Red Sox (Richard Fitts and Cooper Criswell), Mets (Tylor Megill and Paul Blackburn), and Orioles (Cade Povich and Trevor Rogers) all have players on the rotation bubble who they could at least theoretically make available in trade talks with the Mariners, should improving rotation depth be key to a deal from Seattle’s perspective.