USC senior running back Silas Redd was playing in only his fifth game of the season when he injured his knee last week at Cal. Now he'll miss another one after USC ruled him out for Saturday's game against Stanford.
Redd suffered a left knee injury last spring, which kept him from playing in the first five games this season.
Since his return, Redd has carried for 351 yards, including a 19-yard run and a touchdown at Cal before landing awkwardly on his right knee.
Running back Tre Madden, who has been dealing with a hamstring injury, is listed as probable. He has been backed up by redshirt sophomore Javorious Allen, who has gained 268 yards and scored five touchdowns in USC's last two games.
USC is 7-3 (4-2 Pac-12 South Division). Stanford is 8-1 (6-1 Pac-12 South Division).