STANFORD, Calif. -- Linebacker and leading tackler Shayne Skov is out for the season with a left knee injury, dealing a blow to No. 5 Stanford’s bid for a Pac-12 title and national championship.

The school made the announcement Monday. Skov injured his knee in the second quarter of the Cardinal’s 37-10 victory at Arizona on Saturday night.

Arizona receiver Juron Criner was tackled and knocked into Skov’s leg on the play. Skov spread out on the field for about a minute, then had to be helped to the sideline. He lay on a training table behind Stanford’s bench with his knee heavily wrapped before he left for the locker room on a cart just before halftime.

Skov led Stanford with 84 tackles last season to go with 7 1/2 sacks. Even though he didn’t play in the second half Saturday, Skov still leads the Cardinal with 19 tackles this year.

The Cardinal have a bye this week and host UCLA on Oct. 1. They face UCLA, Colorado, at Washington State and back home against Washington before traveling to Southern California on Oct. 29. The only other major test will be the biggest one Nov. 12, hosting Oregon at Stanford Stadium.

Outside of Heisman Trophy hopeful Andrew Luck, there might not be a more important player on The Farm than Skov, and there’s certainly not a more important defensive player. His contributions go well beyond tackles and sacks.

The middle linebacker relays most of the calls to teammates and oversees audibles at the line of scrimmage. The signature eye black that Skov spreads liberally around his face and his mini-mohawk cut have also become staples on the Stanford defense.

The injury could also have significance beyond this season.

The 6-foot-3, 251-pound redshirt junior was expected to enter the NFL draft in April, although he could delay the jump. His brother, Patrick, is also a freshman fullback on the team.

Jarek Lancaster played in Skov’s place for most of the second half Saturday. Sophomore Blake Lueders and redshirt freshman A.J. Tarpley also are options.

No. 6 Stanford rolls past Arizona