Rafael Montero of the Mets pitches in the first inning...

Rafael Montero of the Mets pitches in the first inning against the Miami Marlins at Citi Field on Monday, Aug. 29, 2016. Credit: Jim McIsaac

Had the Mets got their way during the 2013 season, Rafael Montero might be a fixture at Citi Field rather than just a cameo performer, as he was filling in Monday night for Jacob deGrom in a game loaded with wild-card implications. Turns out, in a story relayed by an official from a rival team, the Mets wouldn’t part with Montero in trade discussions with his club that year.

The pitcher they preferred to move at the time? Stunningly, it was deGrom, who still was a season away from the majors. But the Mets’ potential trade partner didn’t want deGrom, so the negotiations fell apart over Montero.

Oops.

In retrospect, for a star-crossed franchise, that was among the Mets’ luckiest breaks as deGrom evolved into the 2014 Rookie of the Year and remains one of the game’s elite young arms. Those types of near-misses aren’t all that unusual, with hundreds of prospects in play every season. But it took a while for the fates of these two pitchers to cross paths again Monday, when the Mets’ decision to skip a tired deGrom opened up a spot for Montero, who was promoted straight from Double-A Binghamton.

Montero’s five scoreless innings helped lay the tracks for plenty of late heroics, from the bullpen’s clamp-down efforts to Yoenis Cespedes’ walk-off homer in the 10th inning of the 2-1 win over the Marlins. Sure, Montero walked six, and required 100 pitches to get through five, but he’s not Matt Harvey. In the final analysis, Montero did enough, and that’s sufficient for the Mets, who also have been hanging on with the likes of him, Seth Lugo and Robert Gsellman.

“We’ve been pleasantly surprised by all of them,” Kelly Johnson said. “We can’t help but be grateful for what they’ve done.”

That’s the alternate reality the Mets are living in, a parallel universe where their NL title defense, as flimsy as it might be, depends on a rotation propped up by replacements. That’s not meant to be a knock on any of them. Just an indication of how vulnerable even the best rotations can be, and the Mets are finishing August with a significant handicap, down deGrom, Steven Matz, and of course, Harvey.

“We think our starting pitching is going to be OK if we get through these next couple nights where we’re going with some inexperienced guys,” Collins said. “We’ve just got to grin and bear it right now.”

The Mets don’t have a choice. If anything else goes awry, like if those bone spurs begin barking inside the elbows of Matz or Noah Syndergaard, it’s pretty much sayonara to the rest of this season. Just last week, however, the Mets took a three-game series from the Cardinals, and the two they won at Busch were started by Lugo and Jonathon Niese. A battered deGrom was responsible for the loss.

But there’s only so far a team expects to go on the depth chart, and Montero was barely in the Mets’ constellation of pitching candidates when this season began. To be fair, Gsellman and Lugo weren’t talked about all that much, either. When it came to reserves, everyone was fixated on Zack Wheeler’s rehab. And that failed, too, delaying him until 2017.

That gives you an idea of how many things had to go wrong for Montero to get the baseball last night against the Marlins — opposite Jose Fernandez, no less. Not the perfect scenario for a stalled prospect hoping for a second chance, but give Montero this much credit — he emptied the tank in keeping Miami scoreless for five innings. That was appreciated by his teammates.

“The job he did tonight was incredible,” Cespedes said through an interpreter.

“Everybody has to pull on their end of the rope,” Collins said.

For as long, and as hard, as they can.

SUBSCRIBE

Unlimited Digital AccessOnly 25¢for 5 months

ACT NOWSALE ENDS SOON | CANCEL ANYTIME