The Red Sox have lost Kevin Youkilis for the season with a torn muscle in his right thumb.

Manager Terry Francona said yesterday the first baseman will have season-ending surgery today in Cleveland for the injury sustained Monday night in a 6-5 loss to the Indians.

Youkilis, who was hitting .307 with 19 homers and 62 RBIs, is expected to be ready before spring training.

Also, the Red Sox reportedly plan to work out veteran first baseman Carlos Delgado, 38, in the next couple of days to see if he could be a possible left-handed complement to Mike Lowell at first base.

Delgado has not played all season after undergoing surgery last year with the Mets.

ASTROS: Houston has signed first-round draft pick Delino DeShields Jr, son of former major league second baseman Delino DeShields.

BRAVES: Atlanta pitcher Kris Medlen was placed on the 15-day DL with a partially torn ligament in his right elbow that could require reconstructive surgery.

NATIONALS: Right-hander Jason Marquis will start on Sunday, his first outing since having bone chips removed from his elbow in May. Stephen Strasburg (shoulder) is scheduled to start Tuesday against the Marlins.

DODGERS: Manager Joe Torre said he expects catcher Russell Martin to miss the rest of the season because of a hip injury incurred Tuesday night.

INDIANS: Catcher Carlos Santana will have surgery today on his left knee and will miss the rest of the season. He was hurt Monday night in a home-plate collision with Boston’s Ryan Kalish.

BRAVES: Tom Glavine‘s No. 47 will be retired before tonight’s game agains the Giants.

METS: Zachary Dotson, a pitcher in the Gulf Coast League, tested positive for Methylhexaneamine and was suspended for 50 games under baseball’s minor league drug program.