Mets pitcher Sean Manaea throws against the Los Angeles Dodgers...

Mets pitcher Sean Manaea throws against the Los Angeles Dodgers during the first inning in Game 6 of the NLCS on Sunday in Los Angeles. Credit: AP/Julio Cortez

LOS ANGELES — During this unexpected in-between phase, with the Mets’ offseason machinations necessarily beginning to turn even as they have played deep into October, one of the looming major questions has become obvious: What will the 2025 rotation look like?

Three of their primary starting pitchers are due to be free agents: Sean Manaea, Luis Severino and Jose Quintana. They started 94 of the team’s 162 games — 58%. That number has shot up to 77% for the postseason, including Manaea’s outing against the Dodgers in Game 6 of the National League Championship Series on Sunday night.

That leaves the Mets with significant holes to fill. They might have some in-house answers, too.

“There’s some questions we have, obviously, with starters this offseason,” David Peterson said. “Being one of the guys that will be on contract coming back, it’ll be exciting to see what they do in terms of rounding it out.”

Before any winter additions, the Mets’ rotation depth chart looks something like this: the enigmatic Kodai Senga at the top, followed in some order by Peterson, Tylor Megill and Paul Blackburn (who missed the final weeks of the regular season and all of the playoffs because of a spinal cord injury). And then there is Jose Butto — a valuable reliever in 2024 — and a bevy of arms who haven’t reached the majors yet, a group headlined by top pitching prospect Brandon Sproat.

The Mets’ offseason options will be many — Corbin Burnes, Blake Snell and Max Fried headline the list of free agents — but their view of internal options will inform how many additions they need to make.

For Peterson, who posted a 2.90 ERA in 21 starts, and Megill, who had a 2.32 ERA in a half-dozen starts in a late-season return from the minors, it could be a chance to emerge permanently from the fringes at which they have spent the first several years of their careers.

“They made huge strides for us,” manager Carlos Mendoza said.

Peterson in particular had something of a breakout season upon returning in late May from offseason hip surgery that solved a years-long issue.

He may well enter spring training next season comfortably penciled into a rotation spot, which would represent a big step up in stature.

“I’m pleased with the numbers and everything like that,” Peterson said at Dodger Stadium on Sunday. “I haven’t really taken a whole lot of time to look at it, but for me it’s exciting to feel the way that I did this year, feel the change in my body. It’s exciting and encouraging going forward that, basically, what I have now is a lot different and a lot better than what I had before the surgery. It’s something to build off of. It gives me confidence. It’s exciting going forward.”

Megill’s year has been messier, lowlighted by demotions to Triple-A Syracuse in June and July. They acquired Blackburn from the Athletics at the trade deadline in part to bump Megill from the rotation. There was thought within the organization that, come spring training, it might be time to try Megill in a more permanent reliever role.

And then he made a bunch of changes and seemed to get better. He added a sinker, which he said helps against righthanded hitters. He moved toward the third-base side of the mound, which he said helps his pitches appear more deceptive. And he started doing more homework on opposing lineups, which helps him pitch with conviction to his strengths and not just the batters’ weaknesses.

It was a relatively small sample size at the end of the season, but it gave Mets decision-makers something to think about.

“Adapt and improvise, man. It’s about always adapting,” Megill said. “A lot of positives to build on . . . I’m just going to continue what I’m doing on that path . . . From a hitter’s standpoint, it’s hard to hit two different fastballs, one that rides and one that’s sinking into the hands.”

The sinker impressed the Mets, too.

“I feel like he’s made a lot of progress, especially with his sinker,” Mendoza said. “It’s becoming a weapon for him. This is a guy that has three, four [above-average] pitches, but the sinker is becoming a real one for him. There’s a lot of progress made for him, and yeah, he’s a big part of this team moving forward.”

Notes & quotes: Jeff McNeil started a second game in a row at second base, a decision Mendoza said was not difficult because the Mets knew they would face lots of righthanded pitchers. He said of Jose Iglesias: “He’s a professional. He gets it. Everybody knows where we’re at. There’s no egos.” . . . Steve Cohen made it to Los Angeles in time for batting practice after going to a Taylor Swift concert in Miami with a couple of his daughters on Saturday . . . Mark Vientos on his sparkly purple cleats: “That way people can see me from the nosebleeds. That’s the whole point. Gotta stand out somehow.”

SUBSCRIBE

Unlimited Digital AccessOnly 25¢for 6 months

ACT NOWSALE ENDS SOON | CANCEL ANYTIME