Giants star catcher Buster Posey is likely out for the season with a fractured bone in his lower left leg suffered during a collision at home plate with Florida's Scott Cousins.

The Giants announced Thursday that Posey was on the disabled list with the injury, a night after he was crushed by Cousins while trying to block the winning run in the 12th inning against the Marlins. He also was scheduled to have an MRI.

Posey has been San Francisco's best cleanup hitter this season, a team leader in the clubhouse and key cog behind the plate for one of the best rotations in baseball. He was batting .284 with four home runs and 21 RBIs, just finding his groove in the midst of a 13-game hitting streak.