Houston Astros outfielder Yordan Alvarez, who was already ruled out for the remainder of this season, had arthroscopic surgery on both knees earlier this week, the team announced Friday.

Doctors repaired a slight tear in the patellar tendon in his right knee, and performed a "routine cleanup" in his left knee.

The reigning AL Rookie of the Year, who played only two games this season, will begin physical therapy and is expected to be ready prior to the start of spring training, the team said.