Toronto Blue Jays centre-fielder Vernon Wells will miss four to six weeks with a strained left hamstring.
Wells was placed on the 15-day disabled list on Thursday, marking the second time in as many days that the Blue Jays shelved a key player due to injury.
Toronto recalled outfielder Kevin Mench from triple-A Syracuse to replace Wells, who landed on the DL for the second time this year.
Wells was hurt while stealing third base in the sixth inning of Wednesday's 9-8 home win over the Baltimore Orioles, hyperextending his knee as he approached the bag and then clutching the area around his left knee.
Wells stayed in the game and scored when Scott Rolen singled to left but did not come out on defence the next inning.
"Going to third, he hyperextended his knee," assistant general manager Bart Given said Thursday. "When you hyperextend it, you put some strain on those tendons. It's not completely ruptured, which is good news, but he's obviously not able to play."
Good news for McGowan
Wells's injury happened on the same day that the Blue Jays announced starter Dustin McGowan will miss at least four weeks with a tear in his throwing shoulder.
Given said the tear in McGowan's rotator cuff hasn't increased in size from last season, when it was first detected.
Film from MRIs conducted last year and Wednesday will still be sent Monday to Dr. Timothy Kremchek, a Cincinnati-based specialist, with McGowan to be examined by him after that to determine whether or not he needs season-ending surgery.
"It's very good news there's no new damage to the shoulder and we'll get started with the rehab next week," Given said. "Surgery doesn't seem like an option at this point."
Wells's latest trip to the disabled list marks his second lengthy absence of the season. He missed two months with a broken right wrist, suffered while making a diving catch on May 9.
Wells, 29, is hitting .289 with nine home runs and 42 RBIs this season, the first of a seven-year, $126-million extension he signed in December 2006.