Arizona Diamondbacks catcher Tuffy Gosewisch suffered a full tear of his left anterior cruciate ligament during a game last week, a further examination revealed, and will need surgery.
Gosewich said his season is over and he'll need six to eight months of recovery time.
Gosewisch was injured trying to beat out a throw to first base on a ground ball Wednesday night in St. Louis. He was tagged out by first baseman Mark Reynolds on a relay from second baseman Kolten Wong after the Cardinals couldn't turn a double play. Gosewisch tumbled after clearing the base and then clutched his knee.
The injury was initially termed a jammed knee before an MRI revealed a tear.
"It's awful, sad. The guy busted his tail to get where he is at, did a great job helping our staff get better, and now he's lost running to first busting his butt to run a ball out and he hit the bag funny. It stinks for him," Diamondbacks manager Chip Hale said.
Gosewich was hitting .211 at the time of his injury, with one home run and 13 RBIs in 38 games this season.
The Associated Press contributed to this report.