Gore rushed four times for 43 yards on the 49ers' opening possession, then headed to the locker room with members of San Francisco's training staff. He came back for one carry on the team's next possession -- a 9-yard run -- then hobbled to the sidelines and did not return to action.
Brian Westbrook filled in admirably for Gore on Monday night, carrying the ball 23 times for 136 yards and a touchdown in the 27-6 victory. Third-stringer Anthony Dixon added 54 yards and a touchdown on 14 carries. That duo will likely split time in the 49ers' backfield if Gore is, in fact, done for the year.
Gore appeared well on the way to his fifth consecutive 1,000-yard rushing season -- through 10 games, he had piled up 801 yards on the ground, as well as 452 through the air on a team-high 46 receptions. If he cannot return to the lineup, this will mark the first time since his rookie season of 2005 that Gore does not hit the 1,000-yard plateau.
The injury would obviously be a huge blow for a 49ers team that's somewhat remarkably still in the hunt for the NFC West title, despite an 0-5 start to the year. Monday's win moved San Francisco to 4-7, just one game behind division leaders St. Louis and Seattle; the 49ers still have one game left against each of those teams down the stretch.