Philip Rivers kept the postseason hopes of the San Diego Chargers alive by leading the team to a 38-35 overtime victory over the San Francisco 49ers Saturday, but there's a chance the five-time Pro Bowler won't be available in the playoffs.

According to ESPN's Chris Mortensen, doctors fear that a bulging disk in the quarterback's lower back is on the verge of being herniated and that surgery may be necessary soon. Rivers played through a rib injury earlier in the year that Antonio Gates described as "very severe" and elected to play through his back injury despite requiring "urgent treament" two weeks ago and almost concluding his season earlier in December, per NFL Network's Ian Rapoport.

The Chargers finish the regular season with a road game against the Kansas City Chiefs, but aren't guaranteed a spot in the postseason with a victory and would need help. If Rivers is unable to continue in 2014, it would likely be Kellen Clemens relied upon to lead San Diego into the postseason.

Rivers finished Saturday night with 356 yards passing, four touchdowns and three interceptions. He is five passing yards away from eclipsing 4,000 yards passing for the sixth time in the last seven seasons.