Bryan Woo is set to rejoin the Mariners’ rotation Wednesday against the Phillies, and that decision gives Seattle something it didn’t have before: a clear read on a starter who had been dealing with right shoulder discomfort.
Woo told club officials he “feels 100% confident” he’s ready to take the ball, and that opens the door for the Mariners to sort through what suddenly looks like a six-man rotation. General manager Justin Hollander said Monday night that the team is still weighing its options and won’t treat six starters as a permanent identity.
“We're going to continue to talk about that as a staff,” Hollander said before Monday’s game at T-Mobile Park. “We haven't made any decisions as of today.
I don't anticipate a six-man rotation as like a new thing the Mariners are going to do for the rest of ‘26 and ‘27 and ‘28, and we're just going to be a six-man rotation team. We'll evaluate the situation as we go.”
Woo’s status had been the key reason Seattle brought up top prospect Kade Anderson over the weekend, and the left-hander made his MLB debut Saturday in the spot Woo would have occupied. Anderson was always part of the Mariners’ late-season thinking, though, and now that MLB Pipeline’s No. 5 overall prospect is in the majors, Hollander indicated he’s staying put.
That pushes Seattle back into the same kind of starter surplus it had earlier this season before Luis Castillo was moved at the Trade Deadline. For now, the club intends to keep rolling with six starters, but Hollander said the final shape of the rotation will depend on how those arms hold up through the late-season stretch and how they’re performing.
He also left open the possibility of going back to a piggyback setup.
“The results do matter, as do how guys are feeling,” Hollander said. “So we'll take all that into account, and we'll make a call as we need to make a call.”
Woo’s latest scare came after he left his Aug. 16 start in Houston following 75 pitches with what he called an “unusual” issue. But after his first bullpen session off the mound, he sounded upbeat about where things stood.
“He had never felt anything like that before,” Hollander said. “He has not been able to reproduce it since then.
It felt a little sore in the couple days afterward; felt nothing out there [on Sunday]. He felt great.
So he feels ready to go.”
Seattle has also been managing extra rest for George Kirby and Bryce Miller since the All-Star break. Hollander said Miller dealt with lat discomfort during a July 24 outing at Texas, which led to him being pushed back a day before his next start.
Miller’s results have been rough for a while now. The Mariners have lost his last eight outings, and over that stretch he has a 7.19 ERA. That run includes Sunday’s 19-2 loss to the Cubs and last Tuesday’s 22-0 defeat in Milwaukee.
“We checked in with Bryce again yesterday ... and he's not concerned about how he feels right now, was the report that I got,” Hollander said.
“Bryce is not making excuses at all, and I don't think he wanted it to come off that way. I do think he was a little bothered by some lat soreness when we pushed him back.
He has not been on the injury report since Aug. 2.
He did not want to have an MRI at that time, and even as late as 20 minutes ago, [he] expressed that he feels good and ready to go.”
The rotation question also ties directly into Seattle’s bullpen, which has been stretched thin. Since the All-Star break, that group has a 6.81 ERA, second highest in MLB. Carrying six starters means one fewer arm in the bullpen, a real squeeze under the current 13-pitcher, 13-position-player roster limit.
There may be some relief coming on Sept. 1, when roster expansion allows clubs to add one pitcher and one position player.
“There’s just different challenges,” Hollander said. “It’s not as much of a challenge if you have six starters and they’re all pitching six innings at the top.
When you have six starters and getting much shorter outings than that, it's a huge challenge. But we will figure out a way to do the right thing for the Mariners and the right thing rest-wise for the starters.”
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