Washington State quarterback Connor Halliday was carted off the field in the first quarter of the Cougars' 44-17 loss to USC on Saturday with what coach Mike Leach said after the game is a broken leg.

The injury, which takes Halliday out for the rest of the year, ends the senior's college career.

Halliday, the national leader in passing touchdowns, passing yards and completions per game, appeared to have his right leg caught under USC defensive lineman Leonard Williams after completing a 14-yard pass on third down. He stayed on the ground in obvious pain.

Trainers appeared to be putting an inflatable cast on his right leg before he was carted off the field.

He was replaced by backup Luke Falk, who completed 38 of 57 passes for 370 yards, two touchdowns and an interception.

Coming into the game, Halliday had 3,833 passing yards, 32 touchdown passes and 10 interceptions. Halliday had thrown for 40 yards and an interception against USC when he was injured.

The Associated Press contributed to this report.