TCU coach Gary Patterson said he was hopeful Boykin could return to action next week against Oklahoma.
"I think Trevone will be back," Patterson said. "We just couldn't take a chance. They said he shouldn't go, and I said, 'OK.'"
Asked whether the ankle was sprained, Patterson said, "I think so."
The senior rolled the ankle after a tackle early in the contest. He remained in the game for the bulk of the first quarter but was clearly hampered before finally heading to the locker room shortly before the second quarter began. He returned to the sideline during the second quarter but did not return to the game.
Boykin was replaced by backup quarterback Bram Kohlhausen during TCU's first offensive series in the second quarter.
Boykin, a Heisman Trophy contender, entered the game with 3,373 passing yards, 19 touchdowns and nine interceptions while adding 597 rushing yards and eight touchdowns on the ground.
Information from The Associated Press was used in this report.