Tempe, AZ (SportsNetwork.com) - After tearing the ACL and LCL in his left knee during Sunday's game, the Arizona Cardinals placed safety Tyrann Mathieu on season-ending injured reserve on Tuesday.
Arizona head coach Bruce Arians revealed the injuries on Monday, saying that the former LSU star will undergo surgery later this month and isn't likely to be medically cleared for the start of next summer's training camp.
Mathieu had his left leg tangled while fielding a free kick that followed an Arizona safety during the third quarter of the Cardinals' 30-10 victory over the Rams on Sunday. He remained on the ground in obvious pain before being carted to the locker room.
The 2013 third-round pick had started Arizona's last 10 games at safety and currently ranks second on the team with 68 tackles. Mathieu added two interceptions, one sack and nine passes defensed during his strong rookie season.
Arizona elevated safety Curtis Taylor from the practice squad to fill the vacated roster spot.