Mariners make 5 roster moves, reveal piggyback plans for Miller and Castillo

1:44 AM UTC

SEATTLE -- The Mariners made five roster moves before Monday’s series opener vs. the White Sox, and also announced how they’re going to piggyback and in the immediate.

Miller will start Tuesday’s game and Castillo will follow out of the bullpen. But the outlook beyond this turn through remains fluid.

And here are the roster moves:

Miller was just activated from the 15-day IL and made his season debut last Wednesday in Houston, and he looked sharp -- aside from a quirky sixth inning that featured an umpire injury delay and threw off his rhythm at the very end.

Castillo, meanwhile, is coming off his most encouraging start of the season -- also in Houston, but last Thursday -- after a seven-start stretch in which he had a 7.79 ERA and the Mariners went 1-6.

It’s also possible that the Mariners use a pivot reliever in between.

“That’s something that we'll look at during the game and see how it rolls,” Mariners manager Dan Wilson said. “But yeah, certainly, that's always a possibility.”

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.

The Mariners aren’t necessarily committed to the piggyback being permanent, or that it’ll always be Miller and Castillo who are the tandem. But 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.”

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, when there was quite literally no one left. 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 -- albeit with the caveat that he’s also had notable injuries for the past 14 months that have limited him to just 19 starts since the beginning of the ‘25 season.

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.

Speaking of, that’s why Ortiz was brought up and Gonzalez was sent down, the latter having pitched each of the past two days.

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 for Tacoma, with a 1.69 ERA, 12 walks and 18 strikeouts.

Wisdom, meanwhile, will give Wilson another right-handed bench bat, and potential backup to Colt Emerson at third base, after the No. 1 prospect was recalled on Sunday and made his much-anticipated debut. The Mariners intend to play Emerson on most days, but there could be games against tough lefty starters where they opt to sit him.

The addition of Davis to the 40-man came shortly after the 26-year-old slugger reached an assignment clause date, on May 15. Had he not been added, he could’ve asked for his release. Davis has another clause on the Minor League deal he signed last offseason in which he can opt out, on Aug. 1.

Davis was a surprise breakout in Spring Training, and he’s continued that production at Tacoma, with a .942 OPS, eight homers and 27 RBIs in 38 games.

Also, Victor Robles remains on a rehab assignment at Tacoma after playing in 10 games while recovering from a right pectoral strain.