Bryan Woo will get multiple extra days of rest on the heels of Kade Anderson making his major league debut.
EDIT: The story was updated at 6:12 p.m. PT to include recent reports of the Mariners planning to return to a six-man starting rotation.
SEATTLE — The long wait is finally over as one of the best pitching prospects the Seattle Mariners, or the MLB, has seen in years will make his major league debut this weekend.
Left-handed starting pitcher Kade Anderson (No. 5 MLB Pipeline top 100) will make his major league debut for the Mariners in the second of a three-game series against the Chicago Cubs at 4:15 p.m. PT on Saturday at T-Mobile Park.
With the debut also came a shift in the rotation for Seattle. Right-handed starter Bryan Woo was originally slotted into Saturday's matchup. However, on the heels of experiencing shoulder discomfort in his last start against the Houston Astros on Aug. 16, Woo will get a couple extra days of rest and won't start at all in the series against Chicago.
Bryce Miller will start the series finale against the Cubs on Sunday, and the team will re-slot the rotation for the second leg of the six-game homestand in a three-game series against the Philadelphia Phillies, which will take place at 6:40 p.m. PT on Sunday.
"He was scheduled to go tomorrow but will likely get slotted in here at some point," Mariners manager Dan Wilson said in a pregame interview Friday. " ... We don't anticipate an IL (stint)."
Per Wilson, the injury isn't expected to be one that will land Woo on the injured list and he hasn't undergone imaging on his shoulder. This follows the train of thought Woo had after his start against the Astros, in which he downplayed the severity of the ailment.
Woo finished with a quality start against Houston despite his shoulder injury. He struck out five batters, walked one, hit another and allowed two earned runs on three hits (two homers) in six innings of work. It was the 2025 All-Star's first quality start on the road since May 12, which was also against the Astros.
Woo has a 4.10 ERA this season with 137 strikeouts in 138.1 innings pitched across 24 starts.
Wilson was also unable to provide clarity on whether or not Anderson's major league call up is permanent for this season, and if it would will result in Seattle returning to a six-man rotation or piggyback setup, as it did earlier in the season.
"I think we continue to talk about that and see what will make the most sense for us going forward," Wilson said. "And I think once we get Bryan slotted in, we'll figure out exactly how we'll proceed. ... (Anderson's) here to start for us tomorrow and I think, going forward, I'd imagine it's similar."
However, it seems like returning to a six-man rotation is exactly what the M's have planned. Per a report from Seattle Times reporter Adam Jude published two hours after Wilson's pregame interview, the Mariners, at least for now, are planning on returning to a six-man rotation featuring Woo, Miller, Anderson, Emerson Hancock, George Kirby and Logan Gilbert, per a source.
