Woo or Gilbert? The Mariners’ Opening Day Starter Debate

He was deeply unfortunate to miss almost the entirety of the playoffs, and his ability to go deep and cover excess exposure of bullpen arms may have ultimately cost them in the ALCS against Toronto. He goes into 2026 with high expectations. The expectation is he will be high again in Cy Young voting, with the ability to even be a potential dark horse in that race if Tarik Skubal has a down year. The Mariners will be looking for Woo to build on his 2025 performance and lead this rotation deep into the playoffs. In previous seasons, the Mariners have rewarded the previous year’s best-performing pitcher with the Opening Day start, as they did with Logan Gilbert. This year will put this theory to the test.

Logan Gilbert: The Team’s Ace

If the Mariners had all five of their starters healthy and performing at their best going into game 7 of a playoff match, you would be hard-pressed to find someone who would not want Gilbert on the mound. His ceiling is the highest of any pitcher in their rotation, and while Woo was their best performer in 2025, Gilbert has been their strongest performer over the last 5 seasons.

If they go with Gilbert, they are rewarding longevity and his role as the leader of this pitching unit. Gilbert will also be in conversations over a long-term extension. The Mariners, without the deepest pockets in the league, will have to be creative to make sure he never reaches free agency. Giving him the nod as the front man of this staff would show how much the organization values him in the Pacific Northwest. While 2025 was not his best season, his numbers in several key categories still ranked among the best in baseball. His splitter is one of the best pitches in the league, and his ability to miss bats is elite, highlighted by a career-high 32% strikeout rate.

The Mariners have long viewed Gilbert as the staff ace in Seattle, and Opening Day starters often reflect that identity as much as recent performance. Following a down year, Gilbert has already made moves to ensure he is back to his peak in 2026. He has spoken openly of his desire to stay in Seattle, so if he lands the Opening Day job, it will be because of his longevity and a hint towards his potential long-term future within the organization.

The Final Decision

Whether Seattle rewards Woo’s dominant 2025 season or reaffirms Gilbert’s status as the staff ace, the decision of who they will name as their Opening Day starter will say a great deal about how the Mariners view their rotation heading into 2026.