"He's not going to play anytime soon," Richt said. "I wouldn't count him out for the rest of the season, maybe the bowl."
The knee injury is "significant" but team doctors won't know how severe it is until the swelling goes down later in the week, Richt said. Lumpkin isn't expected to need major knee surgery, Richt said, but arthroscopic surgery is a possibility.
Lumpkin, who has 37 yards on nine carries this season, missed a game earlier this year due to a broken thumb but has played too much to receive a medical redshirt, Richt said.
Walk-on running back Kalvin Daniels of Dodge County will leave the scout team and join the varsity to provide depth at the position. Daniels has eight carries for 44 yards this season.