SEATTLE – What lingers as one of the great hypothetical questions in Mariners history — what if Bryan Woo was healthy last October? — also bleeds into the outlook for the Mariners this year.

How good can they be with a full season of a fully healthy Bryan Woo?

A year ago, Woo affirmed his place among the game’s elite pitchers, posting a 2.94 ERA across a career-high 186.2 innings, with a 198-to-36 strikeout-to-walk ratio, earning his first All-Star selection and finishing fifth in the American League Cy Young voting.

The 26-year-old right-hander will make his first start of the season Saturday against Cleveland. By design, the Mariners scripted the rotation schedule to have Woo start the third game and thus give him an extra day’s rest on Thursday, the team’s first off-day.

The Mariners had also delayed, by just a few days, his first start in spring training last month, trying to maximize his gradual build up after he missed most of the playoffs last October with a right pectoral strain. Woo had an 85-innings increase in his workload from 2024 to ’25.

Woo said this week he’s feeling “great” physically, and no one has hinted any reason to think otherwise.

The Mariners, though, will continue to be deliberate about finding time and space to give their youngest starter pockets of downtime.

“Consistency is really what I try to take the most pride in my job and my role in the team,” Woo said. “And if I can stay consistent with my plan and my routine week to week and all the little things that we do to get prepared for each start, just hitting those benchmarks every week … you just continue to raise your floor.”

The stability within the starting rotation — Logan Gilbert, George Kirby, Luis Castillo, Bryce Miller and Woo are in their fourth season together, and Emerson Hancock has been a consistent presence, too — has built an open and trusting communication process between pitching coaches Pete Woodworth and Trent Blank and the training staff.

Gilbert, Kirby and Miller all missed significant stretches with injuries during the regular season last year, and Miller began this season on the injured list with an oblique strain. The Mariners hope to have him back by May 1, and the team’s goal is obviously to have a healthier season overall from the rotation.

“This is where I think Trent and ‘Woody’ excel, is figuring out who needs what, who benefits the most with the extra off-days, who benefits the most from pitch-count adjustments,” club president Jerry Dipoto said.

With prompting from catcher Cal Raleigh, Woo made meaningful changes to his between-starts routine midway through the 2024 season. The results were immediate, beginning his ascent as a staff ace.

Since Aug. 1, 2024, Woo has thrown 254 innings across 41 starts, tied for the fifth most in MLB, with a 3.04 ERA that ranks ninth. He began last season with 25 consecutive starts of at least six innings, a franchise record.

“The physical side of his (routine) was huge for him, but his emergence in the game isn’t because of any physical adjustments,” Woodworth said. “His ‘stuff’ isn’t any different than it was in ’23. The heart and the mind and the (fortitude) have gotten bigger. It’s the grit and it’s the consistency of your mindset.

“It’s not about the right drill or the right amount of rest. It was him coming to terms with himself and pushing past wherever he was.”

Woo’s career ERA of 3.21 ranks as the best in Mariners history (among pitchers with at least 70 starts), and his overall strike rate (57.3%) and first-pitch strike rate (67.9%) also rank No. 1.

“You can’t have a bigger jump from where Bryan was as a (2021) draftee to where he is now,” Dipoto said. “In five years, he’s gone from kind of an unknown sixth-rounder coming off Tommy John (surgery) to one of the best pitchers in the American League. It’s pretty incredible, and I don’t think he’s done getting better.

“His intellect, his focus, his work habits — it’s just on a different level.”