The Mariners have made five roster moves before Monday’s series opener against the White Sox. They also announced plans to ‘piggyback’ Bryce Miller and Luis Castillo.
Miller will start Tuesday’s game, with Castillo following out of the bullpen. The outlook beyond this turn through remains fluid.
Castillo’s Role Change
Castillo is coming off his most encouraging start of the season, after a seven-start stretch in which he had a 7.79 ERA and the Mariners went 1-6.
Mariners manager Dan Wilson said that the team may use a pivot reliever in between Miller and Castillo. “That’s something that we’ll look at during the game and see how it rolls,” Wilson said. “But yeah, certainly, that’s always a possibility.”
The Mariners aren’t necessarily committed to the piggyback being permanent, or that it’ll always be Miller and Castillo who are the tandem. With Castillo being their least consistent starter through the season’s one-quarter mark, and Miller missing that entire stretch while recovering from a left oblique strain, these were the two clearest for the role, for now.
“Again, this is something that is new to all of us,” Wilson said. “And we’ll kind of learn as we go.”
Miller’s Return From Injury
Miller was just activated from the 15-day IL and made his season debut last Wednesday in Houston. He looked sharp, aside from a quirky sixth inning that featured an umpire injury delay and threw off his rhythm at the very end.
Beyond Tuesday, how this all shakes out is still a work in progress, the byproduct of having six healthy starters. The club opted for each among that group to make a scheduled start the first turn through upon Miller’s return, and it could’ve conceivably done so again leading into Thursday’s off-day.
Relief Experience and Roster Impact
Castillo has only once pitched in relief over his 10-year career, during the 15-inning marathon in last year’s American League Division Series. He finished that Game 5 win over the Tigers by recording four outs.
Miller has a little more experience in relief but not since reaching the Majors in 2023. During his Minors ascent, there were questions of whether he’d profile better as a starter or reliever, but he’s answered them emphatically.
Another byproduct of this roster construction is that the Mariners are operating one full-time reliever short. So, in theory, they’re going to need even more consistent longevity from the rest of the rotation to keep the bullpen afloat.
Ortiz was acquired from the Dodgers for relief prospect Tyler Gough last November but has yet to make his MLB debut. Ranked the club’s No. 24 prospect prospect by MLB Pipeline, he’s made 15 appearances.