HOUSTON -- Astros outfielder Yordan Alvarez underwent arthroscopic surgery on both knees on Wednesday in Houston, the team announced on Friday. Alvarez, who¡¯s out for the season, will begin physical therapy immediately, is expected to make a complete recovery and should be ready to play prior to the start of next year's Spring Training.

The Astros said Alvarez had a slight tear of the patellar tendon in his right knee, which was repaired, and a routine cleanup was performed on his left knee. Alvarez, the American League Rookie of the Year in 2019, played in two games in 2020 (Aug. 14-15).

Alvarez, who started to experience knee problems last year that lingered into the spring, missed Summer Camp and the first three weeks of the season while he was recovering from coronavirus. He was activated from the injured list on Aug. 14, hitting a three-run homer in his first at-bat and driving in four runs. He played on Aug. 15 but then was scratched from the lineup the following day and put in the injured list a few days later.

Alvarez burst onto the scene last June and his six homers in his first four games. He wound up hitting .313 with 27 homers and 78 RBIs in 87 games, becoming a unanimous choice for AL Rookie of the Year. His 1.067 OPS is a Major League record by a rookie in a single season and the sixth-highest by a player 22 years old or younger since 1900.