Oregon State QB Sean Mannion set to undergo knee surgery

Oregon State quarterback Sean Mannion will undergo knee surgery and be out indefintely. (US Presswire)

Oregon State quarterback Sean Mannion will undergo knee surgery and will be out indefinitely, coach Mike Riley said Monday. The injury happened when Mannion was making a handoff during the Beavers' 19-6 win over Washington State on Saturday, according to the Statesman Journal.

Mannion will not play against BYU on Saturday.

The news puts somewhat of a damper on Oregon State's 4-0 start. Just this week, the No. 10 Beavers were ranked in the top 10 for the first time since the team's Fiesta Bowl season of 2001.

The loss won't be easy for Oregon State to overcome; Mannion has been an offensive catalyst this season. The sophomore is second in the Pac-12 and sixth in the country with 339.5 passing yards per game.

The second-year starter threw for 276 yards and the game's only touchdown in the Beavers' 10-7 upset of then-No. 13 Wisconsin. Mannion followed his performance in the Wisconsin game with a career-high 379 passing yards in Oregon State's upset of then No. 19 UCLA. Mannion then outdid his UCLA performance a week later when he threw for a career-high 433 yards and three touchdowns in the Beavers' 38-35 win over Arizona.

The backup situation at Oregon State is murky, to say the least. Riley isn't big on playing backup quarterbacks, so no other QB has taken a single snap this season.

Cody Vaz will be the starter when the Beavers play at BYU on Saturday. The junior QB hasn't thrown a pass in a game since 2010, his freshman year. Vaz is 6 for 17 in his career for 48 yards. His most extensive action came in a November 2010 loss to Stanford, when he went 4 for 10 for 34 yards.

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