Frank Gore's season appears to have come to an unexpected end.
A source with knowledge of the situation says that the hip injury suffered by the 49ers running back on Monday night will cost him the rest of the 2010 season.
Gore had runs of 25 and 15 yards on San Francisco's opening possession, but went out later in the drive. He returned for two plays to start the next drive, but spent the rest of the first half on the sideline without his helmet.
San Francisco beat up on the Cardinals 27-6 to remain in contention in the NFC West race.
The 49ers announced in the third quarter that Gore wouldn't return for the second half. He had 52 yards on five carries before getting hurt.
Gore is the unquestioned focus of San Francisco's offensive attack, with 203 rushes for 853 yards and three touchdowns.