DENVER — As recently as two-plus months ago the Mets still weren’t sure what they had in Brandon Nimmo.

In need of a roster spot for an extra pitcher and unsure how much Nimmo would get to play if he remained, team officials decided to option the outfielder to Triple-A Las Vegas. Nimmo’s demotion lasted all of three days, after catcher Kevin Plawecki hit the disabled list and the Mets needed another bat.

“That feels like a long time ago,” said Nimmo, who has since emerged as maybe the Mets’ best position player.

The left fielder took a .287/.603/.410 slash line with 12 homers and 22 RBIs into Tuesday against the Rockies, after a career night that followed his Sunday heroics in Arizona, where he blasted a go-ahead homer in the ninth.

In Monday’s 12-2 victory at Coors Field, he homered twice — the first was an inside-the-park job — and finished with a career-best four RBIs. The latter performance came with 75 friends and family members from nearby Wyoming in attendance, including his parents.

“It will be hard to top that one,” Ron Nimmo, Brandon’s father, said Tuesday.

“He is starting to feel comfortable, like he belongs, and I think that’s a big deal and he’s kind of growing into his body. He came up in 2016 and wasn’t as strong as he is now.”

A team official noted he was “moderately” surprised in the 25-year-old Nimmo’s development, and compared the player to Carlos Pena as something of a late-bloomer. Pena, a lefty power hitter, didn’t have his breakout season until he was 26 years old in 2004, when he hit 27 homers for the Tigers.

Paul DePodesta was the Mets vice president of amateur scouting and development when the team selected Nimmo with the 13th overall pick as a high-school senior in the 2011 draft. DePodesta never got to see Nimmo blossom in the organization — he departed to become chief strategy officer for the Cleveland Browns in 2016 — but is now enjoying the scene from afar.

“There were a lot of our people who put eyes on him, so clearly we thought very highly of him,” DePodesta said in a text message. “Both the scouts and the player development people always had a very strong belief in both the player and the person, and sometimes the latter may be even more important. The best part for me is just seeing the smile in all of the highlights.”

DePodesta was criticized in the media and in baseball circles for the Nimmo selection. He was asked if he feels vindicated by Nimmo’s emergence.

“I’m just happy for both Brandon and the Mets,” DePodesta said. “Seeking vindication in these jobs is a bad life choice.”

Brandon Nimmo credits former Mets hitting coach Kevin Long and his assistant Pat Roessler (who has since moved into the head role, with Long in Washington) for retooling his swing and turning him into a power threat.

“We’ve tried to improve my swing and make it more consistent and they also gave me great information — Statcast was saying I was hitting balls hard enough,” Nimmo said. “Though I hit quite a few home runs, I didn’t have the right [launch] angle with them and I was hitting a lot of ground balls. I hadn’t thought of it that way, so I thought of it in a different context.

“I have been able to be more consistent when they make mistakes and that’s been the biggest thing, those swing changes to make me more consistent.”

Ron Nimmo spoke to The Post as he was traveling 100 miles from Cheyenne, Wyo., to Colorado, after he returned home the previous night. The elder Nimmo was anxious to remain in town and watch the final three games of this series before getting to New York next month.

“Earlier this year it looked like he was a fourth or fifth outfielder and there is no place for him,” the elder Nimmo said. “One thing leads to the next and now he is getting to play every day for them. All you can do is the best with the hand you have been dealt, I guess. And he’s pretty good about being even-keeled with that and trying to make the most out of it.”