An MRI after a 40-24 loss to LSU on Saturday night revealed that Patterson tore the posterior cruciate ligament in his right knee.
Patterson, a sophomore, has been one of the bright spots in what has been a forgettable season so far for the Rebels. Patterson completed 63.5 percent of his passes for 2,259 yards with 17 touchdowns and nine interceptions.
Patterson completed 10 of 23 passes for 116 yards with three interceptions against LSU. Juco transfer Jordan Ta'amu, a junior, completed 7 of 11 passes for 78 yards against LSU and will probably start next week's game against Arkansas (noon ET, SEC Network).
The Rebels have lost four of their last five games and are 1-3 in SEC games under interim coach Matt Luke.