Corvallis, OR (Sports Network) - Oregon State quarterback Sean Mannion will miss an indefinite amount of time as he is scheduled to undergo knee surgery in the near future, head coach Mike Riley announced on Monday.
The decision for Mannion to go under the knife was made after the starting QB had an MRI after practice on Monday. According to Riley, Mannion suffered the injury while handing off during Saturday's win over Washington State, but played the entire game.
The sophomore signal-caller has led the 10th-ranked Beavers to a 4-0 record and was averaging 339.5 passing yards per game to go with seven touchdowns and four interceptions.
"It's very disappointing for the young man," Riley said. "He's invested a ton and he's going to miss some time."
Cody Vaz, a junior, will start next Saturday at BYU. He did not play last season.
"Cody is a good quarterback. He's been preparing for this for a long time," Riley said.
10/08 20:41:07 ET