CHICAGO – Knicks rookie RJ Barrett may lack a steady perimeter jumper, but he hardly lacks confidence.

Barrett said he’s looking forward to guarding his Duke compadre Zion Williamson in Friday night’s Rising Stars Challenge at NBA All-Star Weekend and added he would vote for himself – not front-running Grizzlies point guard Ja Morant – for Rookie of the Year.

“A lot of people deserve [Rookie of the Year], a lot of people work hard for it. I don’t know. It’s kind of hard not to vote for myself,” Barrett said Friday morning before a Rising Stars practice at Wintrust Arena, home of DePaul basketball.

Told he really hasn’t been in the Rookie of the Year conversation, Barrett said, “I feel like a lot of guys are playing really good. There’s a lot of good rookies out there. Ja’s been doing his thing all year. Kendrick [Nunn of the Heat]. Zion’s back now. Guys are playing really well. I’m never going to stop believing in myself.’’

The Rising Stars Challenge features the NBA’s top rookies and sophomores divided into Team USA and Team World. That means Barrett, a Canadian who will play for Team World, and Williamson will battle for the second time ever. They faced off in a summer-league game in July, though Williamson was shut down after nine minutes. Williamson was still rehabbing from surgery to repair a torn right meniscus when the Pelicans visited the Garden on Jan. 10. The Knicks will visit the Big Easy on March 27.

Asked by The Post if he wants to guard Williamson in Friday night’s exhibition, Barrett said, “Hell yeah. Hell yeah. I feel like I know better than anybody how to guard him.’’

RJ Barrett of the New York Knicks drives to the basket during a game against the Washington Wizards.
Robert Sabo

Williamson, who got to Chicago at 2:30 a.m. Friday morning after the Pelicans hosted the Thunder on Thursday night, said he’s just “here to have fun’’ and called Barrett “very special.”

“That’s my brother,” Williamson said. “We had great times at Duke.’’

When told Barrett is eager to guard him because he knows things, Williamson changed his tune.

“I’m taking RJ straight to the post,’’ Williamson said with a smile.

Barrett later backtracked slightly when asked if he could share any secrets about defending Williamson, who has been phenomenal since his debut last month. Williamson became the first player since Michael Jordan to post eight 20-point games in his first 10 outings when he dropped a career-high 32 points Thursday night. He’s averaging 22.1 points and 7.5 rebounds.

“I give you a secret: he’s going to do what he’s going to do and you can’t stop it,’’ Barrett said.

“I feel like with him he’s a player that we haven’t really seen before, so how do you guard him? He’s such a great talent. He’s such a great kid. He works so hard at his craft.’’

Barrett, the 19-year-old lefty 6-foot-6 shooting guard, is averaging 13.6 points through 44 games, but his field-goal percentage is 38.8 – including 31.3 percent from 3-point range. His effective field-goal percentage, which gives added weight to 3-point shots, is a lowly 43 percent.

But his crafty instincts in getting to the basket, defense, hustle and intangibles still leave hope he’ll turn into an All-Star, as Morant and Williamson appear destined to be. Williamson was the top pick in last June’s draft, Morant No. 2 and Barrett No. 3.

NBA scouts told The Post during the Las Vegas summer league that Barrett’s swagger would help him as he transitions to the NBA with its emphasis on 3-point shooting, not his strong point.

“I feel I expect greatness from myself,’’ Barrett said. “I work hard to be great every day. I expect great things. Once something like this [All-Star invite] happens, I get to take a step back and enjoy it.’’

RJ Barrett of the New York Knicks speaks at a press conference at 2020 NBA All-Star Weekend.
NBAE via Getty Images

Barrett said he’ll be off to “sunny Florida” Saturday afternoon to unwind after a hectic first half to the Knicks’ season. But first he wants to soak in the All-Star vibes.

“I want to pick people’s brains,’’ Barrett said. “There’s a lot of stars here. It’s chance to talk to them and see what they do and apply it to my life. I saw Gary Payton last night. He was cool and spoke to us and told us how hard he worked and told us to ask questions. Don’t be afraid to ask questions. People have a lot of knowledge.’’

The Knicks entered the break with an interim coach, a GM whose future is up in the air and no official team president. But Barrett is a building block.

“It’s been really different,’’ Barrett said of his rookie year. “I’ve had a lot of people helping me to make my transition smoother. Marcus [Morris], I spoke to a lot, especially because he’s a wing. Wayne [Ellington] and Taj [Gibson] really help me with the day-to-day routine, staying focused all the time.’’

Friday wasn’t just any game for Barrett.

“I watched this game a lot growing up,’’ Barrett said. “I really wanted to be in this.’’