"I'm going to be ready to play in the national championship,'' Lawson said. "I'm going to be back.''
Lawson was ruled out to start the second half. Coach DaboSwinney said Lawson suffered a ligament sprain.
Lawson initially hurt his knee on the first series. He came back on the next series but appeared to reinjure his knee on a sack of Oklahoma quarterback Baker Mayfield. During the ensuing drive, Lawson had a bag of ice wrapped around his knee and a towel over his head and was walking gingerly on the sideline.
He'll have a week and a half to get ready, and said he'll get "as much treatment as I need'' to be ready for the championship game in Glendale, Arizona. He declined to offer any specifics on the nature of the injury, other than repeating that he would be on the field in the title game.
"I could tell it's nothing serious,'' Lawson said. "It's not serious.''
Clemson does not have a replacement with nearly as much experience as Lawson, though his defensive mates did just fine without him Thursday. A unit that surrendered more than 30 points in its past two games sacked Mayfield five times and held the Sooners to 121 yards over the final two quarters.
Lawson, a junior, has already declared for the NFL draft.
Information from The Associated Press was used in this report.
B. Mayfield sacked by S. Lawson for -14 yds
Baker Mayfield sacked by Shaq Lawson for a loss of 14 yards to the Okla 4