CHICAGO -- One of the biggest questions surrounding the Mariners so far has finally been answered -- for now.
Starting pitcher Bryce Miller will come off the injured list and make his season debut on Wednesday in Houston, manager Dan Wilson announced prior to the Mariners’ 6-1 loss on Saturday at Rate Field.
Seattle will deploy a six-man rotation as it grinds through a 13-game stretch without an off-day. Logan Gilbert will start on normal rest Sunday vs. the White Sox. For the four-game series in Houston, George Kirby (Monday) and Bryan Woo (Tuesday) will pitch on normal rest before Miller slots in on Wednesday and Luis Castillo follows on Thursday. Emerson Hancock, who has pitched his way into the rotation while filling in for Miller, will get the nod Friday night against San Diego.
After that, questions around the rotation will once again arise, as Wilson did not commit to the six-man system for long.
“Yes, everyone gets an extra day … but we will kind of recalibrate once we get back,” Wilson said.
Miller’s return has been a hot topic surrounding the club as Hancock (3.21 ERA in eight starts) pitched his way into a starting role, while Castillo, the highest-paid player on the team and one of the most respected veterans in the clubhouse, has had a rough start to 2026.
That continued Saturday when the 33-year-old righty allowed four runs in four innings against the White Sox on a pair of two-run homers. Castillo needed 84 pitches to get 12 outs, and has pitched four or fewer innings in three of his eight starts -- something he did just three times in 32 outings last season.
“I thought his last outing [against Kansas City] was vintage Luis,” Wilson said. “I thought there were flashes of it again tonight, but it was just a situation where they were able to get some pitches on him. The velo was there tonight, I thought the breaking ball was where it had been, they were just able to put some good at-bats on him and get deep.”
Castillo has allowed four or more runs in six of his eight starts to begin the year. Despite the Mariners' starters leading baseball with 229 innings pitched, Castillo has gotten an out in the sixth inning just three times this season.
“I've just got to keep my head up. It’s not how you start, it’s how you end,” Castillo said through interpreter Manny Acta.
But it’s not as simple as moving Castillo to the bullpen. The 10-year veteran has made 251 Major League appearances -- all starts. He’s been one of the club’s most reliable workhorses since 2022.
And it’s not like everything was bad Saturday night. Castillo generated 18 swings and misses, but the White Sox fouled off 22 balls and drove up the righty’s pitch count as he was unable to find his putaway pitch. Castillo reiterated postgame that he feels fine physically.
It’s a good problem to have, to be sure -- six healthy and capable starters. However, the logjam when Miller, who had an outstanding postseason and pitched to a 2.94 ERA across 31 starts in 2024, returns is hard to ignore.
Outside of the six-man rotation, there are a few other options:
- Move Miller to the bullpen as a piggyback option, most likely with Castillo.
- Move Castillo to the ‘pen as a piggyback option for Miller.
- Don’t move either to the ‘pen, but have Miller or Castillo piggyback off each other.
- Move Hancock to the bullpen, given that he transitioned to relief late last year.
The most prevailing thought is that Miller and Castillo will piggyback off each other, but that -- at least for the time being -- both starters will remain stretched out. The club is only one injury away from this entire discussion being moot .
The performance of Miller, Castillo and Hancock across their next few outings could also determine their roles. Don’t expect the six-man rotation to last long -- the Mariners want Woo, Kirby and Gilbert pitching as much as possible.
The temporary plan means Seattle will be a man short in the bullpen, which is already down high-leverage arms Matt Brash (right lat inflammation) and Gabe Speier (left shoulder inflammation). Closer Andrés Muñoz has also been working through struggles.
That won’t last for long, though. At some point, the Mariners will have to decide the long-term plan for their rotation. But it won’t happen the moment Miller comes back.