When Clint Frazier was sent down to the minors in June, his defense was a primary reason why.

Now that he’s back, it seems that’s still the case.

In Monday’s 7-0 loss to the Rangers, Frazier was back in left field and once again, it was an adventure.

He was tested quickly on Monday when he slammed into the left-field wall trying to catch up to Shin-Soo Choo’s double off the wall. Frazier tipped the ball, but wasn’t able to make the play. He got up slowly, got the ball into second base and remained in the game.

“Obviously, I hit [the wall] pretty hard,’’ Frazier said. “I’ve been through hitting the wall and knowing what comes after and those effects were there. I’m feeling pretty good right now.”

It was especially scary since Frazier’s 2018 season was derailed by concussion symptoms that plagued him for most of the year, stemming from a head injury he suffered attempting to make a catch during spring training.

“To see him jar into it like that, running at the speed he was, gets your attention,’’ Aaron Boone said of Monday’s play.

Boone said he was encouraged by Frazier’s interaction with center fielder Mike Tauchman after the play and he was fine when he got to the dugout after the inning.

“I tried not to create thoughts in my head that maybe I am going through something,’’ Frazier said. “But obviously it happened pretty quickly. You try to stay calm. I feel I’m an expert with concussion stuff after last year. If I was feeling any of those effects, I would’ve told them.”

It wasn’t all bad for Frazier defensively. In the fifth, he threw Elvis Andrus out at the plate, as Andrus tried to score from second on a two-out single by Danny Salazar.

“I made some throws home with Scranton the last couple of months,’’ Frazier said. “For it to carry over here is good.”

But Frazier overran Nomar Mazara’s single to shallow left in the eighth.

Before the game, Boone said he didn’t believe Frazier’s glove was as bad as its reputation, since that is part of the reason why the Yankees sent him to Triple-A Scranton/Wilkes-Barre in June — and kept him there until Sunday.

“I really felt like before he went down, I thought we saw a significant improvement,” Boone said. “A lot was made of that one game [against Boston]. You look at the road trip we went on [after that game] and what stuck out in my mind was how well he was playing out there and how good the work he was doing was and has continued down there.”

Frazier was sent to SWB after the game on June 16, when the Yankees traded for Edwin Encarnacion.

He got off to a rough start both offensively and defensively with SWB, but played better before being recalled Sunday, when he went 0-for-2 with a walk as the DH. Mike Ford pinch hit for Frazier in the bottom of the ninth and hit a game-winning homer to beat the A’s.

On Monday, he went hitless again and is 0-for-5 in the two games.