Bryan Woo pitching through lat injury ahead of Sunday's start vs Athletics

Bryan Woo is pitching through a lat injury and could be vulnerable on normal rest when he starts Sunday afternoon against the Athletics at T-Mobile Park, per Yahoo Sports. First pitch is set for 4:10 p.m. ET, with Woo opposing left-hander Gage Jump in the series finale.

The report notes that Woo has been working on extended rest in recent outings but will be on a standard turn for Sunday's assignment. The Mariners have not announced any change to his availability or status.

What happened

Yahoo Sports reported that Woo has been managing a lat injury while continuing to pitch. The outlet noted he could be at risk on normal rest compared to the extended rest he has received in recent starts — a distinction the report treated as meaningful rather than routine.

The Mariners have not announced any roster moves or rotation adjustments connected to Woo's status.

Why it matters

Lat injuries have been a recurring theme in Seattle's pitching staff this week. Two days before Sunday's series finale, the club shut down reliever Matt Brash with right lat inflammation after an MRI revealed additional inflammation; Brash will not throw for eight weeks. The Mariners are now navigating Woo's workload with a similar concern in the background.

Woo's ability to take the ball keeps him in the rotation at a time when Seattle has little margin for error. The Mariners enter Sunday on a three-game losing streak, sitting 66-77 and seven games back in the AL West. Their wild-card position is precarious: the club ranks eighth in the American League and sits 6.0 games below the cut line.

The timing of Woo's starts has become a factor in his recent effectiveness. Yahoo Sports noted that he has been pitching on extended rest in recent outings, a schedule that may have helped him manage the lat issue. Sunday's start comes on a standard turn, which the report flagged as a potential vulnerability — not a certainty, but a variable worth watching.

The numbers

Since the beginning of August, Woo has posted a 2.89 ERA and a 4.25 xERA, per Yahoo Sports. He has allowed two earned runs or fewer in four of his five starts during that stretch. The gap between those two figures — the ERA sitting well below the expected mark — is the kind of detail that tends to attract attention when a pitcher is also managing an injury, though Yahoo Sports did not draw a direct causal line between the two.

On the other side of the matchup, Yahoo Sports noted that the Mariners rank 28th in wRC+, 28th in ISO, and 28th in strikeout rate against left-handed pitching over the last 30 days. The outlet also reported that Seattle ranks dead last with a .212 batting average against southpaws in 2026 — a number that frames the offensive challenge Woo's teammates will face against Jump regardless of how the starter performs.

Lawrence Butler has been a notable exception to the Athletics' recent offensive trends. Yahoo Sports reported that Butler has hit .355 with a 137 wRC+ since the beginning of August, adding a 9.2% barrel rate and a 51.7% hard-hit rate during that span.

Where the club stands

The Mariners are 66-77, third in the AL West and seven games back of the division lead. They sit 6.0 games below the wild-card cut line, ranked eighth in the American League, and have dropped three straight games entering Sunday.

Sunday's contest against the Athletics closes out a three-game series at T-Mobile Park. Seattle then hosts the Texas Rangers for games on Tuesday and Wednesday.

The roster has seen considerable movement in recent days. A few days after the club selected the contract of outfielder Stuart Fairchild to fill the spot vacated by Víctor Robles — who went on the family medical emergency list — Seattle absorbed Brash's shutdown and is now monitoring Woo's workload. Rookie Lazaro Montes left Friday's game in the fifth inning with left hip soreness after colliding with the right field wall; x-rays were negative, but his status remains uncertain heading into the weekend.

Mariners manager Dan Wilson was ejected two days before Sunday's game during the series against the Athletics after benches were warned, adding a layer of tension to what has been a difficult stretch for the club.

What we don't know yet

The Mariners have not disclosed the severity of Woo's lat injury, whether he has undergone imaging, or when the issue first surfaced. The report did not specify whether the club has considered adjusting his workload beyond the extended rest he has already received.

It is also unclear whether Woo will remain on a standard turn for the remainder of the season or whether Seattle will revert to extended rest after Sunday's outing. No roster moves connected to his status have been announced.

What to watch

Woo's performance Sunday will offer the clearest read on how the lat issue affects him on a normal schedule. Yahoo Sports noted he could be vulnerable compared to his recent starts on extended rest, but the numbers since August have been solid, and the Mariners' offense against left-handed pitching gives him a relatively forgiving matchup context to work within.

After the Athletics series closes, Seattle opens a two-game set against the Rangers on Tuesday. With the club's playoff position requiring significant ground to be made up, how the Mariners manage Woo's workload — and whether any further roster adjustments follow — will be worth tracking as September continues.