Updated

Central Florida's two-quarterback rotation is now a man short.

UCF coach George O'Leary said Tuesday that junior Rob Calabrese has a torn ligament in his left knee that will require season-ending surgery. Calabrese was injured during a 2-yard touchdown run in the Knights' win at Marshall last week.

Calabrese started the first two games of the season. But UCF then switched to a two-quarterback system with freshman Jeff Godfrey taking over the starting role.

Stanford junior transfer L.D. Crow will move into the backup spot. Redshirt freshman Nico Flores will serve as the third-string quarterback.

UCF is 4-2 this season and 2-0 in Conference USA. The Knights host Rice on Saturday.