Ronny Mauricio of the Mets works out on the field...

Ronny Mauricio of the Mets works out on the field before a game against the Mariners at Citi Field on Friday. Credit: Jim McIsaac

Ronny Mauricio made his long-anticipated and very splashy big-league debut at Citi Field on Friday night, joining a lineup that felt like the future — a lineup that, at least for a moment, let fans forget about the futility of the present.

Brett Baty was in there, too (like Mauricio, he was part of the Sept. 1 call-ups). Francisco Alvarez started and Mark Vientos was available off the bench in the Mets’ 2-1 win over the Mariners, meaning that, at long last, the Baby Mets were assembled as a complete set.

It was a strong showing: Mauricio doubled in his first at-bat, a 117.3-mph laser that was the hardest-hit ball by any Met this year, singled in the seventh and acquitted himself nicely at second, which isn’t his natural position. Baty had a single in the seventh, too.

But there’s more to this September than one good night full of potential. It was more than the 20 or 30 friends and family assembled for Mauricio’s debut. It was more, too, than just seeing if any of these players can be viable everyday pieces for next season (though that’s unquestionably a priority).

The point, as Buck Showalter said Friday, was that the Mets not “give in to this allure of mediocrity.”

There’s a temptation to play out the rest of this season on auto-pilot, but even though this team will be “re-purposing” through 2024, it’s pivotal to make this wasted time count for something. As for the bigger picture, it’s about creating a blueprint for what Steve Cohen has in mind when he talks about a sustainable model.

This isn’t just accomplished by bringing up Mauricio; most teams, the Yankees included, use expanded rosters to test-drive their highly touted minor-league talent. It’s also accomplished by the less obvious but likely more important moves the Mets made Thursday. They parted with four major components of their talent acquisition, development and performance team, according to a source: the director of player development, director of pro player evaluation, director of performance and director of baseball development.

While general manager Billy Eppler has yet to publicly confirm the changes, the moves illustrate where the Mets think they need to improve: minor-league development, professional scouting and health and wellness.

The massive shake-up is further indication of Cohen’s markedly unsentimental approach: He’s shown time and again that he’ll give things a chance, but when he decides it’s time to switch the approach, those changes will be swift and decisive.

We saw a glimpse of it last offseason, when he didn’t outbid Texas to keep Jacob deGrom in Flushing, and we heard it loud and clear during this year’s trade deadline, when he unceremoniously blew up this team with the unwavering determination of Wile E. Coyote holding a bundle of TNT.

It makes sense for him to keep that approach throughout all of his dealings, including how he treats this young talent. (And how he continues to restructure their player development assets.)

Mauricio will get his shot, but the organization wants him to prove that he can handle the shift in position (the natural shortstop spent his time in Triple-A this year working at second, short, third and leftfield). They want Vientos, who slots in as a designated hitter, to play a position, too, as shown by Showalter’s attempts to get him comfortable at third base. They want Baty to learn how to not let offensive struggles translate into defensive struggles, and vice versa.

All of these guys are playing for their meal ticket, and all of them are being tested for adaptability, teachability and upgrade potential. It’s tempting to look at the trio and think it’s another Brandon Nimmo-Jeff McNeil-Pete Alonso, especially after days like Friday, but the road there is long and craggy.

Don’t think they don’t know it, by the way. About his previous stint with the big club, Baty said he was “trying to make every single play over there and try to be perfect,” and it ended up doing more harm than good.

“The reality is, nobody’s perfect in this game,” he said.

Mauricio, meanwhile, is fully aware of how fans were clamoring for his call-up. “I want to put on a show for them,” he said Friday. He’ll play wherever, he said. He promised to work hard. He also doesn’t fear the spotlight, it seems.

“I felt really good,” he said. “It’s not one of those things where I was having any fear or nerves in a situation like that. This is what I’ve always wanted. This is what I’ve prepared myself for.”

If you want this team to succeed, that’s heartening to hear, especially when you think about the long haul. It may be a lost September, but don’t be fooled: The stakes are high, and despite one very good day in Flushing, the guarantees are nonexistent.

SUBSCRIBE

Unlimited Digital AccessOnly 25¢for 6 months

ACT NOWSALE ENDS SOON | CANCEL ANYTIME