Mariners' likely Opening Day starter is no longer their best pitcher

Of all the things the majority of other Major League teams can be envious about with the Mariners, their starting rotation is arguably the main focus. Just two seasons ago they had the best statistical rotation in all of baseball, and would have had a shot at this feat again last year if not for injuries to four of their five main starters.

The sky really is the limit for the rotation if it can be healthy again in 2026, allowing for the fact Bryce Miller is already causing some nerves within the Mariners fanbase due to left side oblique inflammation. This aside, the main focus in Seattle regarding the rotation is about who will be the Opening Day starter on Mar. 26 against the Guardians?

Mariners manager Dan Wilson was asked on Sunday if he's ready to name his Opening Day starter yet. As per Ryan Divish of The Seattle Times, he said: "It’s a little early yet. We are still evaluating in some ways, but we’re always open to see what happens as we go. We still have two-plus weeks left, and so we’ll just, again, assess as we go."

It seems all but certain the Opening Day starter will be Logan Gilbert or Bryan Woo, and while Wilson's comments are perfectly reasonable, you have to at least wonder if a decision has already been provisionally made. Gilbert has been pitching every six days and his last start was on Mar. 7, setting him up at least mathematically to be on the mound on Mar. 26 at T-Mobile Park.

Is Logan Gilbert over Bryan Woo as Opening Day starter fair?

If this ends up being the case, it seems fair to ask why the honor will not be going to Woo instead, with him easily being the Mariners' best starter last season. He led the team with a 4.2 bWAR, was the rotation's only All-Star and set a franchise record by pitching at least six innings in his first 25 starts of the 2025 campaign.

Woo finished fifth in AL Cy Young voting and there's the lingering thought that he — and by extension the Mariners — could have done even better. The pectoral injury he suffered in late September cost him almost a month, whereas if he had been available it could have made all the difference for a team which as it was, only fell eight outs short of the World Series.

Further, it's not as if last season was anything new when it came to Woo dominating, with him also being the Mariners' best starter by the end of the 2024 season as he led them in ERA and ERA+, while also finishing second in WHIP. Whether it's compared to Gilbert specifically or the rotation as a whole, the 26-year-old has been the team's top rotation arm over the past two seasons.

However, it's not as if we're discussing some charity case when it comes to Gilbert, just deciding to give him the Opening Day starter role due to his more veteran status, or because he was awarded the honor last season. As much as he did take a step back in 2025, this was due to the combination of a right elbow elbow flexor strain and high standards now expected of him.

Limited to 25 starts, the 28-year-old still produced a 3.44 ERA, 173 strikeouts and an excellent 1.031 WHIP. If he hadn't been compromised by his aforementioned injury, he could have been looking at something more comparable to 2024, when he set single-season bests with a Major League-leading 208.2 innings and 0.887 WHIP, while also throwing 220 strikeouts.

Mariners playing the long game with Bryan Woo

One important factor which might explain why if the Mariners decide to go with Gilbert on Opening Day is Woo's health. The 2025 All-MLB Second Team selection has dealt with injury issues throughout his professional career, including forearm inflammation, a hamstring strain and even being hit in the face by a line drive.

Daniel Kramer of MLB.com explains how the Mariners can find ways to mitigate his durability, including starting Woo later than Opening Day and then manipulate April's four off days to add in extra rest. This is what the M's did last season, not starting the righty on a standard four days’ rest until May, which clearly helped towards his streak of six-inning starts and a career-high 186.2 combined innings come the end of the regular season.

There's been some speculation that Woo is more likely to sign an extension, leading to the understandable suggestion to earn his favor by giving him the Opening Day slot. However, we do believe the Oakland native's main focus right now is to stay healthy, which also played into his decision to turn down an invitation to represent Team USA at the World Baseball Classic.

In terms of his current contract situation, Woo is under team control through the 2029 season, meaning plenty of time to negotiate any potential long-term deal. (Gilbert only has one more year of arbitration eligibility remaining after 2026.) Of course he'd love to be named this season's Opening Day starter, but it's not as if he's going to be crestfallen or suddenly become a disruptive teammate if he misses out, especially with more opportunities in future to get the nod based on his current trajectory.