Russell, a junior, injured his neck during a four-yard run with about six minutes left in the fourth quarter.
Freshman Jarrett Stidham replaced Russell for the rest of the game. Before exiting, Russell completed 16 of 37 passes for 197 yards and two touchdowns.
The school said there is no timetable for Russell’s recovery and he will see a specialist next week. Russell has thrown for 1,907 yards and 27 touchdowns this season.
Baylor coach Art Briles told reporters Russell “would probably be out awhile.”
Baylor has a bye in Week 9 and will play at Kansas State on Nov. 5.
Update on Seth Russell: X-rays & CT scan after game revealed fracture in 1 of bones of neck. Will see specialist next wk. Timetable unknown.— Baylor Football (@BUFootball) October 24, 2015