NFL Network Insider Ian Rapoport reported Monday that Gordon was diagnosed with a grade 2 MCL sprain after undergoing an MRI Sunday night, according to a source. Gordon is expected to be out the next few weeks, but could be back before the end of the regular season if all goes well.
Before exiting the game, Gordon amassed 61 yards rushing and two touchdowns on 10 carries.
"His knee is swollen right now," Chargers coach Anthony Lynn told reporters after the game. "We don't know exactly what it is. We'll get a further evaluation tomorrow, and we'll go from there."
Gordon has battled hamstring issues since he was forced to miss a Week 7 win over the Titans, but Lynn said Sunday's knee injury occurred to the opposite leg.
Gordon leads the Chargers in rushing with 802 yards and nine touchdowns on 153 carries, adding 44 catches for 453 yards and four touchdowns. Any potential lost time would deal a blow to an 8-3 team in the hunt for the postseason.