Michael Porter Jr. (right) of the Denver Nuggets warms up before Game 6 of a first-round playoff series against the San Antonio Spurs on April 25 at the AT&T Center in San Antonio.

While all the buzz for the upcoming NBA rookie class is understandably swirling around Zion Williamson of the New Orleans Pelicans, as well as the Memphis Grizzlies’ Ja Morant and the New York Knicks’ RJ Barrett, another rookie can’t wait to make some noise of his own: Denver Nuggets redshirt rookie Michael Porter Jr.

“Zion is that dude, man,” Porter told ESPN’s The Undefeated recently. “No one really has seen a player like him at his size that can do the things that he can do. But I got a little bag of my own, so I’m hoping to open up the people’s eyes to what I could do. And I think all that other stuff will take care of itself. …

“I can be as good as God wants me to be if my body holds up like I know it will and I work how I know I will. I want to be one of the best players to ever play. And it was crazy, going through what I’ve gone through. But that’s my goal.”

Porter was set to make his NBA debut during summer league after sitting out all of last season recovering from back surgery. Unfortunately, the 21-year-old suffered a left knee sprain in practice on Thursday. A source told The Undefeated that he will miss summer league, but is expected to be healthy in time for training camp.

It wasn’t that long ago that Porter was viewed as a generational talent similar to Williamson. Porter was ESPN’s No. 1-ranked high school basketball player in the Class of 2017. Several NBA scouts previously told The Undefeated that the 2017 Naismith Trophy winner would have been the No. 1 pick in the 2017 NBA draft had he been eligible. Another scout told The Undefeated that he believes the former Missouri forward would have been drafted first overall last year over Deandre Ayton, Luka Doncic and Trae Young had he been completely healthy in 2018.

At 6 feet, 10 inches, Porter could shoot from deep, dribble like a guard, lead the fast break, dunk high above the rim, rebound with authority and block shots.

“I got to see what it is like being at the very top,” Porter said. “Of course it was high school, so it was a little different, but I was the No. 1 player in the country. Everybody was talking about me being this and that.”

It appeared he was unstoppable — until back pains in high school worsened.

“I had been ongoing with some normal back pain throughout sophomore year,” Porter said. “Going into junior year is when I first fell on my back. It hurt, but I tried to play the next day, and it was just sore. And it stayed sore for a while because there was a lot of compensation going on, and my body hurt. But I just kept playing.

“I kept playing through junior year, through senior year of high school, just with some nagging back pain. Always tried to go to different chiropractors, always tried to go to different therapists, to help me get it better.”

“There were times I was ready to give it up. There were just some really, really tough, dark days. I’m not gonna lie.” — Michael Porter Jr.

Porter’s injury woes continued as a freshman at Missouri. Porter said a therapist, whom he declined to name, made his injury worse while at Missouri.

“At Mizzou I kept seeing more chiropractors, and I remember one chiropractor did an adjustment and the pain moved from my back to my hips, and I was like, ‘What’s going on?’ ” Porter said. “And the chiropractor was like, ‘It’s new muscles turning on it.’ And then it stayed with me for like three days, and I noticed my leg getting a little smaller … and I’m like, ‘What’s going on?’

“So I tried to jump at practice on my left leg and I couldn’t jump as high. And so that’s when I knew something was really messed up, and that was like the day before our first game against Iowa State. So that was the scariest thing ever.”

The Columbia, Missouri, native ultimately had an L3-L4 microdiscectomy on Nov. 22, 2018, to treat herniated disks in his back and missed most of his freshman season.

The back injury tested Porter’s faith while he was sidelined. The repetitive workouts with slow improvement drained on Porter. People stopped reaching out to him with support. He asked himself, Why did this happen to me?

“There were times I was ready to give it up,” Porter said. “There were just some really, really tough, dark days. I’m not gonna lie.”

Porter credits God, family and friends for getting him through the dark days. He returned to play in Missouri’s final two games of the season, averaging 14 points and nine rebounds in 25.5 minutes per game. He also came back with a different attitude.

“I was a very cocky kid,” Porter said. “I definitely thought I was that dude. And I didn’t really feel like I used my position as the best player in the country, being a person a lot of people looked up to, to the best of my ability. And I feel like I had some things I had to learn as a man before I was really ready to take that position. It was a thing that God wanted to teach me.”

But heading into last year’s draft, Porter said he still felt doomed about his future. Several team doctors poked and prodded him during the draft combine in Chicago. And with his back a major concern, Porter’s draft stock spiraled. He worked out for the Sacramento Kings, who owned the second overall pick, but hip spasms caused him to miss another key workout with multiple teams just before the draft.

A worried Porter was still invited to the green room at the 2018 NBA draft but with no clear idea of where he would be picked.

“I didn’t even know how much I was gonna drop. I didn’t know where I was going to go draft night. No team would really talk to me,” Porter said.

At the draft, Porter walked around slowly with a hitch, as his injury was still bothering him. Ayton was selected first overall by the Phoenix Suns, and a dozen more picks passed without Porter’s name being called. Finally, with not much to lose and a possible star to gain, Denver selected Porter with the 14th overall pick.

But Porter’s draft dreams had become a real-life nightmare for him.

“I could say it was just a blessing to be picked and stuff,” Porter said. “But if I’m being completely honest with you, that day was not how I envisioned draft day. I envisioned it to be the best day of my life, full of excitement, and once I got drafted to the team there was a lot of excitement. But I also had to fake a lot of it too, because it was tough to see all those guys that I’ve played against and they’re all getting drafted ahead of me.

“And what was even worse was I was sitting in that chair watching draft night in pain. That was before I had my second surgery. I was hurting, and it was tough. It was a tough time. I held my mom and just cried. It was just tough.”

A month after the draft, Porter had surgery on his lumbar spine in Dallas. He spent his entire rookie season rehabilitating and working on his game, while the Nuggets won 54 games and advanced to the second round of the playoffs.

“He’s special. If he can get fully healthy, he will be a star for a very long time.” — Isaiah Thomas

There was some buzz about Porter as he worked out before playoff games, but he never suited up.

On the bright side, he said learned a lot from watching games and traveling with the team during the season.

“I learned how to be professional,” Porter said. “Just learning the schedule, learning the travel, how to recover after the games, watching these guys on the court, how the game’s different in the NBA. I watched how guys separate themselves from other guys and what brings other guys down.”

He also said then-Nuggets guard Isaiah Thomas was a mentor to him last season. Thomas has dealt with his share of setbacks in his own career.

“It was tough for him to have to sit out as it is everybody who has a competitor motor in them,” Thomas told The Undefeated. “We worked everyday together and just pushed each other. I just tried to game him on the mental aspect of the game because he has all the physical tools to be a superstar in this league. …

“He’s special. If he can get fully healthy, he will be a star for a very long time.”

While the first day of the Las Vegas Summer League on Friday will be highlighted by an opening-night matchup between Williamson and former Duke teammate Barrett (ESPN, 9:30 p.m. EDT), Porter again will be forced to watch from the sidelines.

“You feel bad, because the kid has been putting in a lot of work, and he was excited to play,” Nuggets assistant coach Jordi Fernandez said. “But obviously the most important thing for him is to be ready for the NBA season. Again, it’s nothing major.”

Before Porter’s latest setback, Fernandez was impressed by his play.

“I’ve been fortunate to be around really good players, and what I see from him is special,” Fernandez said. You see things and you don’t want to say, ‘Whoa’ too loud, but, yeah, you see it. He’s pretty special.”

After everything Porter has gone through, there might not be another rookie who will appreciate playing in a basketball game next season as much as he will.

Still, the Nuggets do not plan to rush Porter back into action.

“While we are all very excited about the potential impact that he can have, we also don’t want to put too much pressure on him,” said Nuggets president of basketball operations Tim Connelly. “He’s really hard on himself because he holds himself to such a high standard. Convincing him that this is going to be a process has been challenging. Which speaks to his competitiveness and love for the game. He wants it so bad.”

He’ll just have to wait a little while longer to make his highly anticipated debut.