MILWAUKEE — Knicks rookie RJ Barrett had never played a home/road back-to-back with a plane ride in between.
He didn’t take to it.
In the worst performance of his rookie season, Barrett went 0-for-9 from the field, finishing with two points and one assist in 20 minutes Monday night. Twice he drove to the basket and got blocked underneath, seemingly a guy running on fumes in the Knicks’ 132-88 loss to the Bucks.
“Tough night — back-to- back,” Barrett said. “First time going through this. It was tough but that’s what I like about being a rookie, being able to learn things on the fly.”
The Knicks had two other back-to-back sets — one was comprised of two home games, the other a game in Brooklyn followed by a Garden match.
“He looked like a rookie today,” coach David Fizdale said of the third pick in the draft. “Sometimes that’s what he’s going to look like. But it’s a good learning lesson for him. I remember days watching Giannis [Antetokounmpo] looking pretty crappy when he was 18, 19. That’s part of the deal for these young guys, going through the lumps of the league.”
Barrett, who is averaging 15 points, got his first chance to see Antetokounmpo (29 points in 22 minutes) up close.
“He’s a freak,” Barrett said.
The Bucks are on a 12-game winning streak and are the favorites in the Eastern Conference. Barrett said facing greatness will help his development.
“You see what it takes to win,” Barrett said. “To be a champion, it’s good for us to play against these type of teams. But you got 45 minutes to think about it and [we] got another game on Thursday. I don’t care about what happened in the game before. You have to look forward to the next game or your mind will go all over the place.”
Before the game, Barrett was on the court with assistant coach/shot doctor Keith Smart, going over some free-throw technique issues. If there’s been one disappointing part to Barrett’s rookie season, it’s his free-throw shooting, which stood at 52.4 percent entering the night.
Ironically, that was the only part of his game that looked OK Monday as he was 2 for 2 from the line.
“I was 100 percent, so I’m good,” Barrett said. “I shoot them every day. Last game [vs. Boston], I missed a couple in a row but I was good the whole game. I’ve been better since I’ve been working on it.”
The concern is Barrett will draw a lot of fouls in his career with his driving ability and needs to be efficient from the line. Former Knicks shooting coach David Hopla, addressing the Knicks’ league-worst free-throw percentage, told The Post he noticed a technical glitch in Barrett that has yet to be fixed.
“He has his balanced hand or non-shooting hand on top of the ball, which can obstruct vision,” Hopla said. “When you shoot it, it adds movement to the right. His balance hand should be more on the side of the basketball for less motion and it is not involved in the shot. More motion decreases accuracy.”
On this night, Barrett couldn’t find his mojo, missing both of his 3-point shots.
“NBA, you’re going to have some of these games,” Barrett said.