It’s been nearly two years since Zack Britton suffered an Achilles tendon injury that required surgery, but it gave him a scare in the eighth inning of the Yankees’ 4-3, 11-inning win over Oakland.

The left-hander left the game during an at-bat against Marcus Semien after he retired the first two batters he faced in the inning.

“It was the side where the Achilles was repaired,’’ Britton said of the right calf cramp. “It didn’t make any sense to push it to a point where I did something pretty serious, especially with all the work I’ve done coming back. It’s been feeling great this year. It was more out of precaution than anything.”

Chad Green, who manager Aaron Boone had hoped to stay away from, entered and walked Semien, as well as Robbie Grossman and Matt Chapman, to load the bases before getting out of it by striking out Matt Olson to keep it a tie game.

Afterward, Britton said he was “fine,” but admitted the Achilles still isn’t back to what it once was.

Boone said the initial news made him “nervous,’’ but added the training staff was confident it wasn’t a major issue. Team physician Dr. Chris Ahmad checked Britton and told him the Achilles was uninjured.

“Maybe if I was a little younger, I would have stayed out there,’’ Britton said. “I felt it with the first hitter I faced and with Semien it got more serious. Last year [coming back from surgery], I would feel a cramping sensation and they said it was normal because it takes a while to build that muscle back. This year I hadn’t felt anything. I hope maybe it’s just dehydration.’’

The Yankees likely have enough bullpen length to give Britton some rest if it’s deemed necessary, but they’ll need him in October, especially considering the state of their rotation.