Mets pitcher Edwin Diaz throws during a spring training workout on...

Mets pitcher Edwin Diaz throws during a spring training workout on Feb. 16 at Clover Park in Port St. Lucie, Fla. Credit: Newsday/Alejandra Villa Loarca

JUPITER, Fla. — Set aside for a moment the mass of the unknowns related to the Mets’ bullpen — yes, there are many — and figure that some but not all go the way the Mets desire.

Then consider a question that plagued the organization for much of last summer: Who will be the closer?

The Mets’ most likely answer seems to be the same as it was last year: Edwin Diaz, who a year ago was a marquee offseason addition and who now has no designated bullpen role, as manager Luis Rojas is waiting to formally name a closer. But if the Mets prefer Diaz in more low-leverage situations to start — if they want him to regain some confidence and re-earn the ninth-inning gig — they have an unusually high number of relievers with closing experience from which to choose.

“You look around the league,” pitching coach Jeremy Hefner said, “and on paper we’re up there with anyone in terms of being able to run out experience, talent, all those things.”

Including Diaz, the Mets have five relievers who have been closers.

Diaz’s 2019 was a well-documented disaster (including a 5.59 ERA), but the Mets believe he can return to the level of success he had in 2016-18, when he totaled a 2.64 ERA. He was an All-Star closer for the Mariners in 2018.

Dellin Betances, the Yankees import, has the longest track record of dominance among Mets relievers — with success in most any inning, ninth or otherwise. He averaged 10 saves per season in 2015-17 (sometimes because of injury and trade-related absences by Aroldis Chapman).

As he recovers from a partially torn Achilles tendon, Betances hasn’t pitched in a Grapefruit League game yet but has said he expects to be ready for Opening Day. He said Thursday that he usually likes to pitch in 6-8 games during spring training, and there is still plenty of time for him to reach that mark. He is slated for another live batting practice session Friday.

Jeurys Familia, like Diaz, was bad last season (5.70 ERA). But Familia, unlike Diaz, already knows what it is like to be a dominant closer in New York, having been an All-Star with a franchise-record 51 saves in 2016. He might be a definite third on this list, but if he has indeed found his splitter again — as early results suggest — he has a shot at looking more like the Familia of old.

Justin Wilson, who was very good when healthy for the Mets last year, was the Tigers’ closer for part of 2017.

Brad Brach, who re-signed with the Mets on a one-year deal, closed for the Orioles during parts of 2017-18.

And then Hefner made sure to mention Seth Lugo, the Mets’ best reliever the past two years, and Robert Gsellman. Lugo has dabbled in save situations in recent seasons.

“Lugo and Gsellman have some of the best stuff on the team,” Hefner said. “Those seven guys, legitimately any one of them, I would feel comfortable with them closing at any point.”

Then again, Hefner also said the concept of a closer competition in camp “is news to me.” So perhaps the Mets already have decided internally and simply haven’t revealed their choice yet.

In discussing the so-called closer’s mentality — the intangible idea that a reliever needs a certain killer instinct to be able to handle high-pressure save situations, and if he doesn’t have it he doesn’t have it — the analytically inclined Hefner acknowledged that it might exist. And it seems the Mets have several bullpen arms who already have shown it.

“It definitely takes a certain person to be able to close a game,” Hefner said. “We’re talking about something that’s really hard to measure, so I struggle to understand how to coach it. I think some of it is just how you’re born, your DNA. Do you have a slow heartbeat? It’s just the way it is in some guys. That’s how I think about it.”