The Yankees will be without a key piece of their bullpen for the rest of the year.

Jonathan Loaisiga told reporters on Saturday that he has a torn ulnar collateral ligament in his right elbow and will undergo season-ending surgery.

He is expected to miss 10-12 months after having the surgery, which will be performed by Dr. Keith Meister, according to MLB.com.

The reliever specified that the procedure is not Tommy John surgery.

Loaisiga had landed on the 60-day injured list on Friday after Aaron Boone said the right-hander was dealing with a “significant forearm strain.”

“Obviously, it is concerning,” Boone said before the Yankees’ 3-0 loss to the Blue Jays. “We’ll see what we have now over the days and weeks and where we go from here.”

Loaisiga, 29, pitched four scoreless innings this year over three appearances, striking out three.

He is a free agent after this season.