San Francisco Giants catcher Buster Posey suffered a broken left ankle and may have torn ligaments in his left knee following a collision at home plate Wednesday night, CSNBayArea.com reported Thursday.
Posey, the reigning National League Rookie of the Year, had to be helped off the field after Marlins outfielder Scott Cousins came crashing into home plate during the 12th inning of the Giants' 7-6 loss.
"It's way serious," a source told Comcast SportsNet, explaining that an X-ray taken at the ballpark revealed the fracture to Posey's ankle.
Posey, 24, was slated to undergo an MRI Thursday morning, which would confirm the extent of ligament damage in his knee.
The young star would likely miss the remainder of the regular season should the injuries prove to be as serious as early reports indicate.
Posey was in visible pain following the play at the plate, during which Cousins scored the eventual game-winning run.
According to Comcast SportsNet, the Giants have already called up minor-league catcher Chris Stewart. Backup catcher Eli Whiteside figures to start against the Marlins Thursday.