The same injury could keep the Wildcats' leading rusher out for this weekend's game as well.
According to the Arizona Republic, Grigsby is officially listed as questionable for the game Saturday against Cal.
Grigsby is averaging 7.5 yards per carry on his 71 touches, and has score five touchdowns on the ground.
The Cats are actually 4 deep at this position.
The big concern for Arizona is the DL getting pressure on Riley.