Noah Clowney showed up at Alabama as a modest recruit, barely ranked in the top 100 nationally in the freshman class.

Less than a year later, the teenager has arrived in Brooklyn as a first-round draft pick.

And however impressive last winter’s meteoric rise was, Clowney — with a self-awareness that belies his tender age — is quietly confident he can make even more strides this winter as a Nets rookie and again in the years to come.

After all, the young big man has exceeded expectations before. Why not again?

“I think I’ve got a lot more to my game than what people [have] seen,” said Clowney, the No. 21 pick — the first of many picks the Nets received in return for superstar Kevin Durant.

“But obviously I was playing with Brandon [Miller], and we didn’t need to be another star on that team. So I played my role to help us win. That’s really all there was to it.”

Clowney arrived in Tuscaloosa as an underrated talent, just 99th in 247 Sports’ ranking of the Class of 2022. And he was overshadowed by Miller, who was picked second overall by the Hornets in last Thursday’s NBA Draft.

But Clowney managed to impress in his lone season at Alabama, not just with his 9.9 points and eight rebounds per game, but with his impressive length and switchable defense.

And after his workout for the Nets on the Tuesday before the draft, the team even considered trading up from No. 21 to get him.

Turns out they didn’t need to. The Nets — who opened business Friday by re-signing Cam Johnson to a four-year, $108 million deal and unloading Joe Harris to the Pistons — got to keep valuable assets, and still got one of their primary targets.

“I had a few teams in my head that I knew might want me,” Clowney said. “I knew after my workout that I was pretty solidified that if I made it there to that pick that they were going to get me.”

Clowney fell into a pattern by Nets general manager Sean Marks of drafting a center every other year: Jarrett Allen in 2017, Nic Claxton in 2019 and Day’Ron Sharpe in 2021.

He also joins the latter pair in hailing from the Carolinas — Sharpe from Greenville, N.C., and Claxton from Greenville, S.C., just 30 miles from Clowney’s Dorman High School alma mater.

South Carolina hasn’t lacked in talent — from Kevin Garnett to Khris Middleton — the Spartanburg-bred Clowney relishes the idea of being next in line after young standouts such as Claxton and Zion Williamson.

“Yeah, I take pride in that,” Clowney said. “I’m the first person to go to my high school, they just told me, to get drafted. Coming from where we’re from and to get drafted out of there, it’s big. The scouts [are] not really coming to South Carolina to watch anybody play.

“So as far as the draft goes, it was surreal. And I know a lot of people probably say that same word, but I saw all the cameras coming so I knew it was me, and then they actually called my name. It’s just an unreal feeling. It was great.”

At 18 years, 342 days old on draft night, Clowney became the second-youngest draft pick in Nets history, two days younger than previous record holder Derrick Favors (2010) and behind only fellow 2023 draftee Dariq Whitehead.

“We don’t like numbers,” Clowney said on the “Voice of the Nets” podcast with Chris Carrino.

“The high school ranking, number where you’re drafted, none of that matters. If you’re given an opportunity, you either take advantage or you don’t. That’s [it]. It’s only two outcomes. … So for me, I always had like a chip [on my shoulder].”

He always had measurables. And talent.

“I can’t teach 7-foot wingspan,” Marks said, nodding toward Clowney.

Clowney’s wingspan is a reported 7-foot-3, to be precise. Clowney fits the profile of a modern big man, switchable and comfortable on the perimeter, with a jumper and floor-spacing potential.

“Offensively I can bring a lot: spacing the floor, decision-making, a bunch of different things offensively,” Clowney said. “Defensively is where I hang my hat. Guard multiple positions. We protect the rim. We do it all. …

“Whatever you ask me to do defensively, it’s going to get done. That’s pretty much it. Now, five men in the league are bigger, stronger, so I got some time to put on some more weight. I’ve put on like maybe 12 pounds since the season ended. I got some more time to put on weight.”

Clowney readily acknowledges that need to bulk up. This past season, he was listed at 210 pounds, stretched over a wiry 6-foot-10 frame. A dozen pounds would be a solid start, but he’ll need more if he’s going to bang in the post with All-Star centers the likes of Nikola Jokic and Joel Embiid.

Meanwhile, he’ll need to become a more consistent shooter to face the basket and play power forward.

“I know my capabilities and I know I can listen, so when they tried to change my jump shot in high school I knew I could change my form and I could become a good shooter,” Clowney said. “As far as volume, sh-t, coach told me let it fly, so I let it fly.”

At Alabama, Clowney hit just 28.3 percent of his shots from 3-point range on more than three attempts per game. Two prolonged droughts (0-for-10 and 0-for-21) lowered his efficiency, but his form was fairly sound and he showed an ability to hit from the corners. Doing that more consistently will be his pathway to getting playing time as a rookie.

“This offseason my last two months I’ve been perfecting my shot,” Clowney said on “Voice of the Nets.”

“That was the main thing. If I can make shots, make open shots, even semi-contested shots, now [I’ll] open up the rest of my game. I can do a lot more, because now you’ve got to really close out. You’re not closing out short [any] more. When you close out fully, now I get to drive downhill, make decisions. So there’s a lot more that can be shown when I’m more of a consistent shooter.”

Despite leaving Alabama after just one season, Clowney plans to go back for his degree and become a mental health counselor.

“I had my own issues like eighth through 10th grade,” Clowney said on the podcast. “People always tell me you’re so mature, you act like you’re old. It’s because when I had my own issues, my mom told me one day, ‘You can’t stress over what you can’t control.’ And that sparked my research.

“I started researching more how the mind works, things like that. And then I just kind of went from there, and ended up going to school for psychology, learned a little more in my one year there, and then I just want to help other athletes.”

Nets assistant Trevor Hendry will coach the Las Vegas Summer League team. The team will include Clowney and fellow rookie draft pick Jalen Wilson, as well as David Duke Jr., whom the Nets declined to tender a qualifying offer, making him an unrestricted free agent.

Adonis Arms, Armoni Brooks, Kennedy Chandler, RaiQuan Gray (who spent last season with G League Long Island), Jordan Hall, Kameron Hankerson, Matt Lewis, Trey McGowens, Nick Perkins and Jamorko Pickett make up the rest of the roster.

The Post has confirmed a report by L’Équipe that the Nets will play in Paris during the 2023-24 season.

The French outlet reported they will face the Cavaliers in an expected January game.