Stanford is making a switch at quarterback.
Costello for its game Saturday at No. 25 Washington State, coach David Shaw announced Thursday.
A win Saturday would keep the Cougars viable in the Pac-12 North race, where they now sit in third place behind Washington and Stanford. Junior running back Bryce Love was ruled out of the game because of last week's ankle injury, and the offense struggled without him.
This gives new meaning to "Pac-12 After Dark". Most of the offense comes through the air, as Luke Falk has thrown for 2,576 yards and 23 touchdowns this year.
Costello completed 15 of 24 passes for 173 yards and a touchdown in a 34-24 win over Arizona State on September 30 in his only previous start.
With Love on the bench last week, Stanford produced just 222 yards of total offense in a narrow victory over cellar-dweller Oregon State. He's rushed for 1,387 yards and 11 touchdowns in seven games this season.
The game at WSU is an important one in the Pac-12 North standings. Stanford has won eight of the last nine meetings with Washington State, but the Cougars have covered the spread in the last two encounters. "If he passes that, then hopefully he'll be up".