Reigning US Open champion Brooks Koepka is expected to miss the next 2 1/2 months with a partially torn tendon in his left wrist, according to a statement released by his agent on Friday.

He hopes to be back in time for the Masters.

Koepka’s wrist has bothered him since the Hero World Challenge in early December. He played anyway, finishing last in the 18-man field in the Bahamas. In his next start five weeks later at the winners-only Sentry Tournament of Champions, he failed to break par in any of his four rounds at Kapalua and again finished at the bottom of the leaderboard at 13 over.

“It’s not fun,” Koepka said in Hawaii two weeks ago, unsure of how he sustained the injury. “Nobody can come up with an answer.”

He had planned to play at Phoenix in two weeks and Pebble Beach the week after that.

Koepka, currently ranked eighth in the world, said doctors are unsure when the injury occurred, and an initial MRI did not show a tear. After the Sentry Tournament of Champions, he received a second opinion and that is when the tear was discovered.

The initial diagnosis calls for eight to 12 weeks of rest and therapy and a full recovery is expected for the 27-year-old, the statement said.