A key piece of the Yankees’ bullpen last season is starting this year from behind.

Jake Cousins reported to spring training Tuesday with a forearm strain, manager Aaron Boone said, and is in the midst of a three-to-four-week shutdown.

The righty reliever is “a couple weeks” into the no-throw period, per Boone, meaning he could start a throwing program as early as next week, but even that puts his status for Opening Day in question.

“Seems like it’s going well and he’s on track to start throwing hopefully at some point next week or the following week and then build up from there,” Boone said at George M. Steinbrenner Field. “So, that could leak into Opening Day perhaps. But we’ll have to see.”

Cousins, who missed time late last season with a pec strain but returned for the playoffs, had a UCL injury in 2022 but decided against having Tommy John surgery and instead treated it with a PRP injection.

The Yankees acquired Cousins from the White Sox shortly after Opening Day last year and the cousin of Falcons quarterback Kirk Cousins went on to become an important weapon for Boone.

Cousins posted a 2.37 ERA with 53 strikeouts across 38 innings in the regular season.

As for other offseason injuries, Boone said right-hander Clayton Beeter “had a little shoulder issue that it looks like he’s through.”

Beeter, a starter who could become a relief option in the big leagues, is already throwing sides but is still behind in his buildup.