Coach Billy Donovan said the senior forward has a bone bruise in his right knee. Prather had some swelling in his knee after Wednesday night's win against South Carolina, and team doctors initially thought he might have torn cartilage. But tests Thursday revealed no structural damage.
Prather is averaging 17 points a game this season and leads the Southeastern Conference in shooting at 62.4 percent.
Point guard Scottie Wilbekin, who left Wednesday's game with a sprained right ankle, sat out practice Thursday and Friday but should play. Donovan said he's unlikely to start, though.
Center Patric Young (sore knees) also missed practice Thursday.