Oregon State's fairy tale season hit a possible dam break Monday when it was revealed starting quarterback Sean Mannion would be lost for an indefinite period of time because of a knee injury.
Mannion has completed 63% of his passes this season for 1,358 yards and seven touchdowns. Oregon State has been this year's biggest surprise, rebounding from a 3-9 season with a 4-0 start that has landed the school at No. 10 in this week's Associated Press poll.
Mannion played the entire game Saturday in Oregon State's 19-6 win over Washington State but was intercepted three times.
Oregon State must turn now to junior Cody Vaz, who has limited experience. He completed six of 17 passes for 48 yards in 2010.
Oregon State plays at Brigham Young this week.