NEW YORK -- The Mets won’t know entirely what to expect from Kodai Senga in National League Championship Series Game 5 on Friday, but they do know he’s likely to be a part of the proceedings.

Senga is a strong candidate to start Game 5 despite his issues in Game 1 on Sunday, manager Carlos Mendoza said. And even if Senga doesn’t start, he could appear in the game in relief.

“He’s an ace, man,” Mendoza said. “This is a guy that we saw making a start against the Braves [in July], and he was lights-out. He pitched against the Phillies, and he was throwing 96, 97. It was one pitch that [Kyle] Schwarber got him, but other than that, he was pretty good. And then we’re reacting off one outing that he didn’t have it. So I’m pretty confident in giving him the ball.”

Much will depend upon whether the Mets use David Peterson or Tylor Megill in relief in Games 3 and 4. If neither is a well-rested option for Game 5, the Mets will start Senga in Game 5 without much deliberation, according to a person familiar with the team’s thinking. But if Megill is available, some within the organization believe he would be a better candidate to start. In that case, Senga could potentially appear out of the bullpen, but it would depend upon the flow of the game. In a close contest, the Mets might go straight from Megill to their high-leverage relief arms. In a blowout, they would be more likely to turn to Senga.

(While Peterson is also an option to start Game 5, he stands a strong chance of appearing in relief at some point before then, which would probably take him out of play for a bulk assignment Friday.)

The other school of thought is that Senga represents the Mets’ top option regardless. He was, after all, their best pitcher last season, producing a 2.98 ERA over 29 starts. And he was effective in two of his three outings this season, including a July 26 start against the Braves and an NLDS Game 1 start against the Phillies. Only in NLCS Game 1 did Senga struggle, throwing 20 of his 30 pitches outside the strike zone and explaining afterward that his mechanics were out of whack.

Senga threw a bullpen session Wednesday and looked significantly improved, according to a team decision-maker, which should bolster the Mets’ confidence in him. He also stretched out in the bullpen following his NLCS Game 1 start, which means an effective Senga could throw as many as four innings and 60-ish pitches in Game 5.

“He knows himself better than anybody,” Mendoza said. “At times, if something’s off, you’re going to see games like that. But if he’s right, he can be lights-out.”

Although one bullpen session represents a microscopic sample size, the Mets don’t have many other data points to evaluate Senga, who missed nearly the entire regular season due to shoulder, triceps and calf injuries. It wasn’t until early October that Mets officials began seriously considering Senga as an option for their playoff roster.

A week and a half into that experiment, they may be no more certain of what Senga can provide them, but they’re still committed to chasing his upside.

“I never thought that he was going to be a player for us,” Mendoza said. “Now, because of where we’re at, you’re going to need somebody to start the game. He’s an ace. … That’s why there’s a chance he starts on Game 5.”