Concerns that Knicks rookie RJ Barrett would be unable to plow to the basket like he did at Duke were mostly wiped away during preseason.

Barrett, the third pick in this year’s NBA draft, was one of the few bright spots of the exhibition season in which the Knicks posted a 1-3 record and looked like a team that still could use a few more preseason games.

But they may have a gem in the 19-year-old Barrett if coach David Fizdale does not wear him out too soon.

The 6-foot-7 shooting guard averaged a whopping 37.4 minutes per game in the four preseason outings. Barrett’s impressiveness was a contrast to last preseason when 2018 lottery pick Kevin Knox struggled so much, he lost his starting job at the outset of the regular season.

“I feel like the Knicks drafted me because they knew what I could do,’’ Barrett said of his driving prowess. “That’s my game. I could do that at any level. I’m going to continue to do that and make reads as much as I can.

Barrett’s outside shot is still suspect, but he did hit a transition 3 during his 19-point outing vs. New Orleans on Friday. He scored 17 points in the first half, but rarely got the rock in the final two quarters. He finished the night shooting 9-of-12. Barrett buried the only 3-pointer he took.

Overall, in the four games, Barrett showed he can play with pace, rebound, move the ball and defend. He averaged 15.8 points, 3.3 assists and 6.8 rebounds, shooting 46.3 percent overall – 33 percent from 3-point land.

“I feel like I’ve played well over the course of the preseason,’’ Barrett said. “It was great for me, get up and down in an NBA game, NBA setting, to be more prepared for the regular season.”

That starts Wednesday against San Antonio, which is led by one of the greatest defensive coaches of all time in Gregg Popovich.

“He’s a very good player,’’ Pelicans coach Alvin Gentry said after the Pelicans beat the Knicks 117-116 in a Garden thriller. “Good scorer. He’s obviously worked on his body and gotten stronger. I think that’s gonna help. He’s a playmaker. He’s a kid learning the game, and you can see he’s going to be a really, really good player in this league for a lot of years.’’

There were scouts at the Las Vegas summer league who felt Barrett’s skill of getting routinely to the hoop in college may not translate against the quick and long defenses of the NBA.

Barrett has yet to do it in a regular season game. but signs points to him being OK because of a burly body and craftiness.

TNT’s Stan Van Gundy pointed out no matter how good rookies such as Zion Williamson or Barrett have looked, teams don’t game plan against players in preseason.

“I said it, man, he doesn’t look like a rookie,’’ Fizdale said. “He’s a tough kid. He really knows how to play and he’s fearless. He’s tough to take out of the game.”

Fizdale wanted to cut down his minutes in the preseason finale but still rolled him 35. The Knicks coach is not concerned yet with burning Barrett out.

”He’s 19,’’ Fizdale said. “I never got tired when I was 19. I got him down to 35 today. He’s hard to take off the floor because he does so much stuff to help you win. But I am going to have to figure out a way to manage him.’’

The rookie wall hits most first-year players — and all in different ways.

“I’m good,’’ Barrett said. “I’m not worried about it. I’ve heard that every rookie hits it. So if I hit it, I hit it and get over it. It’s going to happen at some point. I’m not worried about it.’’

When told Fizdale said he doesn’t look like a rookie, Barrett said, “I’m definitely a rookie. I feel confident out there. I feel like I deserve to be here. I’m not going to back down at all.”

Barrett brushed off the NBA GM poll in which he didn’t get one vote for Rookie of the Year or the category of “rookie who will be the best player in five years.”

“It’s been happening to me since high school,’’ Barrett said. “I’m not worried about it.”

The Canadian southpaw, whose mother is from Brooklyn and whose father played at St. John’s, only cares about a long career in New York.

When asked about whether he’d one day want to play with Williamson, Barrett said, “We definitely thought about playing together in college, but me playing in New York for my whole career, it sounds great to be honest. That’s an honor.’’