Mets pitcher Mike Montgomery during a spring training workout Tuesday, Feb. 23,...

Mets pitcher Mike Montgomery during a spring training workout Tuesday, Feb. 23, 2021, in Port St. Lucie, Florida. Credit: Newsday/Alejandra Villa Loarca

JUPITER, Fla. — The Mets released veteran lefthander Mike Montgomery on Sunday night, one in a series of roster moves that brought the final details of the Opening Day roster into focus.

The Mets have 31 players remaining in major-league camp, which ends Monday, and five of them are injured, leaving the team with the requisite 26-man roster. That suggests Jacob Barnes and Robert Gsellman have won bullpen jobs, though the Mets haven’t officially acknowledged as much.

After entering camp on a minor-league contract, Montgomery impressed for much of spring training but had a rough start in the Mets’ 10-2 exhibition loss to the Marlins on Sunday, allowing five runs in 2 2⁄3 innings.

Montgomery’s other three appearances included no earned runs, but manager Luis Rojas noted that his velocity and command weren’t as good Sunday as usual. He

had an opt-out clause in his contract if he wasn’t added to the Mets’ 40-man roster by Sunday night, which forced them into a decision. When they didn’t choose him, he exercised his right to leave.

"Obviously, I want to be in New York, and I’m pretty confident in myself and my stuff right now," Montgomery said. "I don’t look at a game like today in spring as make-or-break for me at this point in my career."

Those decisions were something of a surprise considering Gsellman can be optioned to the minors and pitched poorly (5.63 ERA) in five exhibition appearances. Since 2018, he has a 4.91 ERA, pitching mostly in relief.

The Mets also informed six players that they did not make the team: Jerry Blevins, Jerad Eickhoff, Caleb Joseph, Jose Peraza, Mallex Smith (opt-out clause this week) and Arodys Vizcaino. They optioned Stephen Tarpley to Triple-A.

"I’ll be going to [and living in] Brooklyn to report to the alternate site," tweeted Blevins, who did not pitch last year. "I feel great. My body and my arm have responded beyond my expectations. Hope to see you all in Queens soon!"

Who’s on first?

Jeff McNeil worked out at first base alongside Pete Alonso and Dominic Smith on Sunday morning. He played the position three times in the minors, and Rojas said he considers McNeil an emergency option there.

"Pete was actually coaching him there and telling him to do some things and they were having fun," Rojas said. "He can be one of those guys that ends up there in a game if a lot of things happen."

Smith started at first base against the Marlins, his first time there since March 8.

Catching up

James McCann said he enjoyed his time this past week with Mike Piazza, who was in Mets camp as a guest instructor. On his first day, the former Mets catcher sought out the current Mets catcher.

"We talked everything — we talked catching, we talked hitting," McCann said. "I took a day where I just picked his brain. I loved hearing him talk, taking it all in."

Extra bases

Jonathan Villar (sore groin) did not play and won’t play Monday, but Rojas said the Mets still expect him to be ready for Opening Day . . . Vizcaino (sore right elbow) pitched in a game for the first time in two weeks, working around a leadoff walk for a scoreless inning against Marlins minor-leaguers. His fastball consistently was 95-97 mph. "Seeing his velocity, seeing his off-speed pitches, I think he’s a guy that could really help us," McCann said . . . Edwin Diaz struck out the side but allowed three runs (four hits), the only runs he allowed in six Grapefruit League games . . . Brandon Nimmo hit a home run about 400 feet into the open door of a truck beyond the right-centerfield wall.