James Paxton is indeed headed toward season-ending surgery after receiving a second opinion on Monday on the left forearm strain that he sustained during his 2021 debut.

Mariners manager Scott Servais revealed the course of action ahead of Tuesday’s doubleheader against the Orioles in Baltimore, and he wasn’t certain if it would be Tommy John surgery.

Regardless, it’s a huge blow for Paxton — who has battled significant injuries throughout his career and was determined to get through a season healthy for the first time in his ninth year — and the Mariners, who are down an innings-eater they were counting on for the six-month haul less than two weeks in.

The Mariners signed Paxton to a one-year, $8.5 million deal on Feb. 18 with the understanding that there was risk, given that Big Maple’s 2020 season with the Yankees ended after five starts — and a career-high 6.64 ERA — due to a flexor strain in his pitching forearm.

Paxton exited his start against the White Sox in Seattle on April 6 after 1 1/3 innings, and he said then that his latest injury was related to that flexor strain. Neither he nor the club was concerned about the status of his forearm after he wowed in a December bullpen session in front of roughly 20 clubs interested in signing him, then looked stellar in Spring Training.

“It’s kind of been a process through the recovery of my flexor strain from last year, throwing this offseason, going into bullpen [sessions], getting in Spring Training games,” Paxton said after exiting on April 6. “And that process was all going well. I was going through the levels, kind of building it up. And I just came into tonight, I was pretty confident that I was going to be good. But it turned out that it just was a little bit too much for what my flexor was ready for.”

Paxton was thrilled to return to Seattle after spending two years with the Yankees, seasons headlined by the highs of pitching in the postseason in 2019 and blemished by the lows of battling through back surgery ahead of the ’20 season, then entering his first foray into free agency while recovering from the flexor strain. He said this spring that he had multiyear offers from other clubs, but the comfort of returning to the organization that he grew up in ultimately swayed him above all.

Big Maple turns 33 on Nov. 6 and will be a free agent. If his rigorous work ethic to bounce back from the many other injuries he has overcome are any indication, he’ll be determined to work just as hard in his recovery again.

“If I know Pax, he’ll take the right attitude with it and go forward and try to make the best out of it and come back hopefully stronger than ever,” Servais said.

Lewis return next homestand? ‘Very realistic’
The Mariners could be returning their top run producer from 2020 as soon as this weekend. Servais said Tuesday that it’s “very realistic” to anticipate that center fielder Kyle Lewis will be activated from the 10-day injured list during Seattle’s homestand against the Astros and Dodgers, which begins Friday.

Lewis has remained in Seattle with the alternate training site roster while the club has been on the road, and he took four at-bats in a simulated environment on Monday. Lewis will still need to work in some defensive reps in the outfield, but all signs are positive for the reigning American League Rookie of the Year Award winner.

“He’s moving in the right direction,” Servais said. “He’s starting to get at-bats. So he’ll get some timing down and things like that. He hasn’t really gone full-out testing it in the outfield yet, but he feels fine. Everything he’s done to this point, swinging the bat, and he’ll continue to build upon that.”

The Mariners’ offense has stayed afloat despite not having its everyday cleanup man. That has largely been thanks to the Nos. 1-3 hitters in the order — Mitch Haniger, Ty France and Kyle Seager — who each has been the difference in at least one of Seattle’s five wins entering Tuesday’s doubleheader. Injecting Lewis, who had 17 homers and a 127 OPS+ over 76 games the past two seasons, will be a warm welcome.