Sawyer is starting in place of Trevone Boykin, who injured his ankle during a win against Kansas last week. Sawyer relieved Boykin in that game, completing one of seven passes for 42 yards and a touchdown.
Boykin entered the season as a Heisman hopeful. In 10 games, the senior has completed 65.8% of his passes for 3,427 yards, 29 touchdowns and nine interceptions.
The Horned Frogs are ranked No. 18 in the latest college football playoff rankings. Oklahoma is ranked No. 7 after a win over Baylor last week.