Nestor Cortes is back in the rotation, at least for now, but he added he’d be OK with pitching in relief in the postseason.

The left-hander, who made his first appearance out of the bullpen since 2021 on Saturday, when he came in after Clarke Schmidt and finished a win over the Cubs with a 4 ¹/₃ no-hit innings, said afterward he was “upset” about the move, saying he’d been a “workhorse” in the rotation.

“Now they do this,’’ Cortes said of the change in role.

Aaron Boone said he understood Cortes’ frustration.

Now, Cortes is set to start Thursday against Boston in The Bronx, as the Yankees try to sort out their rotation for the stretch run and into the playoffs.

And Cortes understands he may go back and forth again by the time the playoffs arrive.

“I’m happy I’m able to do it,” Cortes said Wednesday of pitching both as a starter and reliever. “I know I was a little [ticked] off about it, but that’s in the past. My goal has always been to win, no matter where I’m at. Whatever helps this team win, I’m gonna do. Of course I’d rather start, but if it winds up I’m coming in for two or three innings, so be it.”

As of now, the Yankees have six legitimate starters, with Schmidt and Wednesday’s starter, Luis Gil, back from injuries, to go along with Gerrit Cole, Carlos Rodon and Marcus Stroman, as well as Cortes.

Boone said the team will have conversations about how to handle a playoff rotation.

“We might pull another guy out or even two,” Boone said. “We’ll consider all that. You’re not sure how many of them would play down there [in the pen] or not.”

Cortes has shown that he can do it and do it well.

“There hasn’t been any conversations with me about whether I’m going to stay [in the rotation],” Cortes said. “I guess it’s a blessing and a curse for me because I’ve done it already and they know I’m capable of doing it.”

As a starter this year, Cortes has been up and down, but was excellent in three straight starts before a rough outing against the Cardinals on Sept. 1.

He rebounded out of the pen Saturday in Chicago, when he entered the game having a rough idea of how many pitches Schmidt would throw in his first game back from a strained lat.

Cortes has stayed on the same routine since then.

“The fact I’m able to do it is a plus for me,” Cortes said. “A lot of teams need that [flexibility] in the big leagues and we need it now — being able to do both roles. I know what to expect out of the pen and moving forward, I’ll adjust to whatever’s needed.”

The 29-year-old made three starts for the Yankees in the 2022 postseason and allowed six runs in 12 innings.

The Yankees lost two of the three games.

“I’m always going to grind,’’ Cortes said. “And I thrive under pressure, so whatever they want to do is fine.”