Nestor Cortes is set to return to the Yankees rotation and start Saturday afternoon against the Astros and manager Aaron Boone expects the left-hander to have a “big” impact despite a quick turnaround.

He has been out since May 30 with a left rotator cuff strain and was initially scheduled to make a third rehab start on Wednesday for Triple-A Scranton/Wilkes-Barre.

Instead, Cortes was put on the fast track back to the majors after Domingo German was placed on the restricted list Wednesday so he can undergo treatment for alcohol abuse.

“I guess feeling-wise, I was ready to go,” Cortes said Friday before the Yankees and Astros played in The Bronx. “It was more of the buildup that I was doing during that third rehab outing just because my pitch count wasn’t high enough.”

Cortes said he is looking forward to the opportunity.

“Great. Excited,” he said with a smile about the start Saturday. “Hoping these next 24 hours is quick so I can get it going already.”

In the first half of the season, Cortes fell short of his 2022 All-Star season campaign, when he was 12-4 with a 2.44 ERA over 28 starts.

In the 11 games and 59 ¹/₃ innings he has pitched so far in 2023, Cortes has a 5-2 record with a 5.16 ERA, allowing 58 hits, 34 earned runs, 19 walks, and throwing 59 strikeouts.

Cortes said he believes he can get back to his 2022 form, which is where the Yankees need him to be as they sat within 2 ½ games of the Blue Jays for the final AL wild-card spot entering Friday.

“I thought the first half, obviously the numbers don’t show, but my first five innings of work were good and then wheels would fall off in the sixth or seventh inning. Apart from that Texas game that I got hit early, but just to build off that and being healthy because I felt like for some starts I wasn’t completely healthy,” Cortes said. “But I was grinding through it to see if it was going to go away and it didn’t.

“So, I think feeling back to normal now is going to help maybe get a sixth and seventh inning.

“The reason my command wasn’t all there in the first half, I think it was due to some soreness and some stuff that was going on with my shoulder so I couldn’t maybe command the ball as well as I wanted to. Hopefully now being healthy, it will get better. That’s what it’s all about.”

The numbers check out. Cortes has a sparkling 1.84 ERA in innings 1-4 this season, but a whopping 14.67 ERA in innings 5-7.

Cortes told The Post that he has not been given a “specific count” for Saturday and Boone did not provide a pitch number either, but Cortes is “imagining” he will throw 60 or more pitches, which is what he was scheduled to do Wednesday in the canceled rehab start.

“Nestor is a really, really good pitcher in this league. Feel like he’s in a good place physically. I do feel like he’s been throwing the ball well over the last month in his buildups, in his lives, and into his game action,” Boone said.

“So, obviously, not all the way built up yet but I do feel like he could be a big lift for us.”