Harris said Tuesday he hurt the patella tendon and hoped to have surgery soon. He hurt the same knee during the offseason.
Harris appeared to get injured after being flipped over near the sideline by a defender during the 17-10 preseason loss Friday night to Seattle.
He secured the starting job down the stretch last season after season after rushing for 157 yards and two touchdowns in four games. Harris was signed to the practice squad in October and joined the active roster in December.
The Packers drafted Alabama running back Eddie Lacy in the second round. He and Harris were being counted on to solidify the running game.
Source: Associated Press