Denver’s No. 1 draft pick (14th overall) in 2018, Porter, 21, missed all of what was supposed to be his rookie NBA season as he rehabbed from a second back surgery last summer.

So on Tuesday night, when he sank his first NBA basket in a preseason game in Portland against the Trail Blazers, a 20-foot step-back jumper, the Nuggets bench erupted.

“He’s meant to play basketball, he’s meant to do this and God’s got him,” Monte Morris, who’s been something of a mentor to Porter, told The Denver Post. “Just go out there and do what you’ve been doing all your life.

“People don’t really know how good he really is.”

Porter’s line Tuesday: nine points on 4-for-7 shooting (with one missed 3-point attempt, too) and three rebounds.

After the game, deep inside the Veterans Memorial Coliseum, Porter’s relief was palpable, noted The Post. He was happy that his long-awaited debut went well, but he was over the novelty of it.

“Man, this is just a blessing,” he said. “I just need to enjoy this and be proud of myself, this is my dream come true to get out there and be an NBA player.”

Here are five things we learned from Michael Porter Jr.’s long-awaited Nuggets debut:

  1. He’s a long way from being completely comfortable.

Injuries aside, just not taking part in competitive five-on-five game action against an actual opponent left more than a little rust.

“I kept playing with the ball because I couldn’t get a feel for it,” Porter said. “I was gonna make a move before I did, but the ball was feeling weird, so then I just dribbled again and then did a sidestep.”

Nineteen months is 19 months. Time and game minutes should only help.

  1. He showed flashes of what the Nuggets envisioned.

Remember, Porter, who played only part of one season at Missouri because of the back problems, fell from a possible first overall pick to outside the lottery in 2018 because of questions about his long-term health, with the Nuggets taking the risk.

On Tuesday night, shortly after Porter finally checked in midway through the third quarter, the 6-foot-10 redshirt rookie showed there was nothing amiss with his silky step-back jumper as he went up and over Blazers 7-footer Zach Collins for that first bucket. A few minutes later, he took the ball to Blazers rookie Nassir Little, who at 6-6 had no way to fight Porter’s length and mile-high release point.

Per the Post: “Porter had several of those moments in Tuesday’s exhibition that helped validate some of the hype that had trickled out of Nuggets’ second-floor practice gym this summer.”

  1. He could complement All-NBA center Nikola Jokic.

It wasn’t just the jumpers. Porter flashed moments where he appeared he could be a dangerous small forward complement alongside Nuggets All-NBA center Nikola Jokic, not to mention rising star Jamal Murray.

“Nikola was already talking to me,” Porter said. “When I get inside, people collapse on me, so just looking. I’m gonna be such a better player playing with Nikola because not only is he going to find me, but he’s going to teach me how to, when I attract a crowd, find people.”

Which leads to …

  1. He’ll be looking for a defined role.

On every level of basketball until now, Porter has been used to being ball-dominant.

No more.

He’ll have to adjust to playing off the ball and improve at cutting hard through the lane to get many of his touches.

That’s a challenge offensively, especially as it appears he’ll be fighting Torrey Craig, Will Barton and Juancho Hernangomez for minutes on a team with high playoff expectations.

  1. He has a ways to go defensively.

If Tuesday’s game offered a glimpse of Porter’s skills with the ball in his hands, then it also exposed his shortcomings at the other end of the floor.

Translation: Defensively, he isn’t close to understanding his responsibilities.

“He’s very gifted offensively,” Nuggets coach Michael Malone said. “I’ll watch the film, but my biggest takeaway is that he’s gotta give the defensive end just as much attention to detail as he does the offensive end. He’s a gifted scorer. He can take and make big, big shots and tough shots, but he’s gotta be locked in on the defensive end.”

This was only the first step. In the wake of his long-awaited debut, Porter seemed genuinely excited to dig into the game video, study his miscues as much as his highlights and build toward the future.