ATLANTA — Zack Britton’s nightmare season continued Monday, when the left-hander was placed on the 10-day IL with a left elbow sprain. The move is retroactive to Friday.

The move came a day after Britton had some discomfort and inflammation in the area. An MRI exam on Sunday showed what Aaron Boone called “a small strain.”

The news led Britton and the Yankees to get further opinions about what to do next.

“We’ll probably know more in the next few days,’’ Boone said.

It’s the latest setback for Britton, who battled COVID in the offseason, then had elbow surgery during spring training and a strained hamstring after he first returned to the Yankees.

Clay Holmes was reinstated from the COVID-19 IL prior to Monday’s game against the Braves at Truist Park, filling Britton’s spot in the bullpen.

Britton’s last appearance came Thursday, when he allowed a run on two hits in one inning during a victory over the Twins in The Bronx.

He’s in the midst of the worst season of his career, with a 5.89 ERA and a 1.691 WHIP in 18 ¹/₃ innings over 22 appearances.

Prior to the most recent shaky outing versus Minnesota, Britton had perhaps the most promising appearance of the season, pitching a scoreless eighth inning in a win over Boston.

In that outing, Britton’s velocity was up and he looked to have the sharpness that’s evaded him for much of the year.

But that was short-lived, as his velocity dipped again Thursday.

“I know what a long, tough road [it’s been] and how hard he’s worked,’’ Boone said. “The last couple of outings he was building good momentum.”

Asked if the injury might have led to some of Britton’s recent poor performance — which led the left-hander to ask Boone to take him out of the closer role before Aroldis Chapman returned from his IL stint — Boone said, “It’s tough to say, as far as when it started.

“I feel like he felt pretty good from an arm standpoint,’’ Boone said. “He’s not quite sure. We’ll see what we have. We’ll see the best course of action to get him right.”

They haven’t been able to figure that out to this point after the team picked up Britton’s $14 million option for 2022 to prevent the left-hander from potentially opting out of his deal following last season.

The decision meant the Yankees decided to keep Britton for two years and $27 million rather than possibly see him walk.

But since opting to get bone chips removed from his elbow in March, Britton hasn’t approached the effectiveness he’d displayed for most of his career, as well as with the Yankees.

He called his numbers in 2021 the result of “really just pitching like s–t,’’ earlier this month.

“I’m beyond frustrated at this point,’’ Britton said at the time. “I’m not getting my body to do what I want it to, like last year and the years before that.”

It’s left a hole in the Yankee bullpen, which they’ve helped make up for with surprises like other lefties, Lucas Luetge — a minor league signing in the offseason — and Wandy Peralta, who arrived in a trade from the Giants in April, in exchange for Mike Tauchman.

Still, with the Yankees in position to make the playoffs and perhaps a lengthy postseason run, Britton was expected to play a major role. That’s now again in jeopardy.