Coach Mike Shanahan said Thursday that Sellers would stay in the hospital overnight.
Linebacker London Fletcher, who has played in 214 straight games, was limited with a sore hamstring. Shanahan said it's "hard to even think about a guy like that being out -- he'd have to be out there on one leg."
Backup quarterback Rex Grossman was able to take a few snaps. He was hospitalized this week with pneumonia.