Mariners face a playoff problem even after optimistic Bryan Woo injury update

The 2025 regular season is over, and the Seattle Mariners have several days to bask in the warmth of having clinched a playoff trifecta: a postseason berth, the American League West title, and a first-round bye. For them, the playoffs don't begin until Saturday.

Meanwhile, it seems all is well — or at least trending in that direction — with Bryan Woo.

The All-Star righty hasn't pitched since making an early exit from his start in Houston on September 19, but Mariners fans were sighing in relief as soon as minor pectoral tightness was revealed as the cause. As reported by Daniel Kramer of MLB.com, president of baseball operations Jerry Dipoto said on Sunday that “there’s a good deal of optimism” that Woo will be part of the rotation for the American League Division Series, in which they'll take on either the Detroit Tigers or the Cleveland Guardians.

The catch, however, is that the Mariners can't solidify any plans until Woo throws off a mound. He hasn't done that since his injury, and exactly when he will do so this week remains up in the air.

Bryan Woo's timeline may force the Mariners to get creative with their playoff rotation

In theory, Woo might be good to go for Game 1 of the ALDS on Saturday at T-Mobile Park. He's the obvious choice on merit in the wake of a 2.94 ERA over 186.2 innings. As starters typically throw bullpens in the middle of their time between starts, a session on Tuesday would give him enough time to recover for Game 1.

Yet if Woo partakes in one of the Mariners' intra-squad scrimmages on Wednesday or Thursday, that would make things more uncertain. And given how long it's been since he pitched, Kramer may not be wrong that a start in Game 3 next Tuesday might be the "best-case scenario" for Woo.

In fact, let's take it a step further: That should actually be the Mariners' preferred plan.

Though Woo is hands-down the Mariners' best pitcher of 2025, where he differs from his rotation mates is that he's effective both at home (2.44 ERA, .543 OPS) and on the road (3.40 ERA, .643 OPS). For their parts, Logan Gilbert, George Kirby, and Luis Castillo have each had their ERA and OPS suffer away from T-Mobile Park:

• Logan Gilbert: +2.50 ERA, +.255 OPS
• George Kirby: +1.78 ERA, +.133 OPS
• Luis Castillo: +2.11 ERA, +.253 OPS

Per these splits, the Mariners could benefit most from leading with Gilbert in Game 1 and Castillo in Game 2. This way, they would put their best foot forward at home, with their best possible foot to follow on the road with Woo in Game 3 and Kirby in Game 4, if necessary.

Alternatively, the Mariners could ride the hot hand and start Kirby in Game 2, with Castillo getting held back until Game 4. With Woo's sinker literally in hand, Kirby dominated in his last three starts by whiffing 31 of 64 batters he faced, with only four runs allowed on 11 hits and one walk.

Though Castillo hasn't been a road warrior in 2025, he is the most experienced starter of the bunch. He has a 1.83 ERA in three career playoff starts, notably pitching seven-plus innings in both of his outings for the 2022 Mariners.

Either way, there's wisdom in the Mariners not rushing Woo back for their playoff opener on Saturday. And it's certainly in their interest to be as wise as they can, as even a team as loaded as this one isn't going to get through October on talent alone.