O'Leary is the winner of the John Mackey Award as the top tight end in college football.
He grabbed his left leg and was taken back to the locker room during warmups. He later returned to the field and appeared to be testing his leg while jogging.
The grandson of golfer Jack Nicklaus, O'Leary has 47 receptions for 614 yards and six touchdowns this season, ranking second on the Seminoles in each category.
The Seminoles (13-0) faced Oregon (12-1) in the 101st edition of the Rose Bowl game.