Aroldis Chapman appeared in just five games in September and threw just 4 ¹/₃ innings.

It was by far his lightest workload for any month this season.

Adam Ottavino, Zack Britton and Tommy Kahnle all had their lowest usage rates of the season over the last month as the Yankees set themselves up for what they hope is a lengthy postseason run.

Starting Friday, they’ll figure to get a lot more work.

Ottavino was among those waiting to see if it pays off.

“We’ll find out,’’ the right-hander said.

Aaron Boone said he didn’t intentionally take it easy on his most important bullpen arms down the stretch. It just kind of happened that way.

“I think we played it pretty straight, frankly.” Boone said Thursday at Yankee Stadium. “[We’re] always mindful of their usage, striking that balance between trying to keep them sharp, but keeping them fresh and rested. … That didn’t really change much at all down the stretch.”

Perhaps, but outside of Chad Green — who pitched roughly the same amount as he did the rest of the year — the relievers didn’t work much as the Yankees pivoted from trying to catch the Astros for the best record in the American League to making sure they were in the best position physically as a team.

Ottavino agreed with Boone and didn’t believe the Yankees went out of their way to change anything.

“I didn’t get the sense there was anything different or that they were trying to keep guys out of games,’’ Ottavino said. “It just kind of happened. I’m pretty sure I pitched in the games I normally would have. I just happened to not pitch as much.’’

And Ottavino said it left him in a good spot.

“Physically, I feel good and strong,’’ Ottavino said. “There’s no issues.”

Mostly, he’s just been waiting for Friday to come.

“I’m excited to get to the next step,’’ Ottavino said of his second postseason after he made it a year ago with Colorado. “I wanted to focus on finishing this [regular season] off and now I’m ready to go.”

He spent the past few days trying to stay sharp after pitching — along with the rest of the key bullpen members — in Sunday’s regular-season finale.

“It was tempting to look ahead during the season, but I tried not to,’’ Ottavino said. “I just wanted to stay sharp. I think we did a good job of that.’’