SAN DIEGO — Coming into spring training, just about every pitcher on the roster was working on some sort of cutter. A few months into the season, right-hander Luke Weaver isn’t using his all that often. The Mets’ setup man is only throwing his cut fastball about 13% of the time.

That’s intentional; Weaver has found he doesn’t need to use it in every outing. When he uses it, it’s to keep hitters honest.

“It has a place,” Weaver told the Daily News this week in San Diego. “It has a place that needs to be shown and needs to be allowed to enter hitters’ minds. I think you kind of go on runs where things are working pretty well in different sections of the play, and you’re trying to use it in a strategic way.”

Ultimately, Weaver is seeking a balance in his mix between the three pitches he throws — fastball, changeup and cutter — but at the moment, his philosophy is this: If it ‘aint broke, why fix it?

Weaver hasn’t allowed an earned run since April 30. Over those 14 appearances, he’s allowed only nine hits, walked four hitters, and struck out 19. He’s held five leads, once in a two-inning appearance against the Yankees.

The former Yankees closer is aware of this stretch of games, and yes, he’s made jokes about jinxing it. He attributes it to following his process and being adaptable with it.

“At the end of the day, it’s just stringing together consistency,” Weaver said. “That process has allowed me just to kind of nitpick and find little ways to problem solve in real time out there on the mound, and it’s just been contained, even when it maybe hasn’t been as pretty.”

Weaver tries to stick to the same daily routine, but as a reliever, that requires flexibility. After outings, he goes back through to see what he liked and didn’t like, and how he handled certain situations emotionally. He compares the game plan with the execution to determine where he deviated and why, and when he stuck to it and why.

That’s where the cutter sometimes comes into play. Since Weaver isn’t using the pitch often, he has to work on it in the bullpen to keep it sharp and maintain a feel for it. That postgame process is helpful for understanding when he should use the pitch, but he doesn’t want to throw it without conviction.

“It’s like a kind of a bad domino effect of, ‘Well, I’m not throwing it much when I kind of want to throw it,’” he said. “I haven’t thrown it enough in a game to feel maybe at my full confidence to throw it, and then that leads to another time of not throwing it. So it takes a lot of just mindfulness and practice beforehand to throw it. I’ll get off the mound, maybe pregame feel it out, get the feel, so when it does happen, I just need to trust it.”

Other times, he wants to use it because he has a feel for it.

“Ultimately, I like to use it just for fun too,” Weaver said. But we’re not at a point where it’s 0-0 or we’re up by one [run] where we can kind of just lollygag around and say, ‘Let’s just throw for fun.’ So I think there’s always an excuse that can be made, but there’s intentionality of just saying, ‘Hey, I need to pick moments to use this to set up and take and make my life a little bit easier, really.’”

The Mets’ bullpen has been a strength of the team this season. They’ve pitched the fifth-most innings in baseball, and have the fifth-best ERA (3.19). There may come a time when they hit a wall, given the high usage and the Mets’ tendency to use openers, but at the moment, they’re saving the team.

It might be the group with the most chemistry, and they attribute some of their success to that chemistry.

“It’s pretty high,” Weaver said. “We’re always rooting for our starting pitchers, because they’re the foundation of our team. We’re here to help serve and to help protect those things on the back, and I think that is our whole mindset. We’ve gotten close, we’ve had great times, we hang out a lot, and we want to pick each other up.”