The Tigers announced after halftime that Lawson would miss the remainder of the game.
Lawson was injured during the first quarter and initially returned to the game before sitting back down. He was spotted on the sideline icing his injury as teammates consoled him.
An All-America defender, Lawson made 54 tackles and 9 1/2 sacks this season for the Tigers. The junior announced his plans to enter the 2016 NFL draft earlier this month.
Oklahoma led Clemson 17–16 at halftime, with the winner set to advance to the national championship game against the winner of Alabama and Michigan State.
The Crimson Tide and Spartans meet in the Cotton Bowl on Thursday at 8 p.m. ET on ESPN.
- Jeremy Woo