CORVALLIS, Ore. (AP) -- Oregon State quarterback Darell Garretson will miss the rest of the season because of an ankle injury.
Garretson, who started the first six games for the Beavers, was injured in the second half of Saturday's 19-14 loss at home to Utah. Afterward, he was seen on crutches.
Beavers head coach Gary Andersen announced that Garretson was done for the season at his Monday media availability.
Backup Conor Blount, who was also on crutches following the loss to the Utes, is unavailable for Saturday's game at No. 5 Washington. The nature of his injury was not known.
Andersen said Marcus McMaryion would start at quarterback against the Huskies. There is also the possibility that Seth Collins, who played quarterback for the Beavers last season before switching to receiver, could see snaps.
''We're going to get our best guys on the field in the best situation. I don't think it's going to be any surprise attack if Seth plays at quarterback with what he's done in the past,'' Andersen said. ''We'll see where it takes us. But these kids have a great attitude and they're going to battle.''
Garretson threw for 617 yards this season with three touchdowns and four interceptions before he was injured. A junior, Garretson sat out last season because of NCAA rules after transferring from Utah State.
McMaryion played at quarterback in seven games last season, starting in the Civil War against Oregon. He threw for 403 yards with a touchdown and three interceptions.
In the game against Utah on Saturday, McMaryion completed five of nine passes for 76 yards, including a 14-yard touchdown pass to Hunter Jarmon in the fourth quarter.
Collins started in seven games with the Beavers last season, throwing for 936 yards and six touchdowns, while also rushing for 580 yards and eight scores. Sidelined by injury for four games, he returned in the Civil War, seeing time at running back and receiver.
Collins made the switch to full-time receiver this year, and is the team's leader with 26 catches for 286 yards.
Former Utah State quarterback Chuckie Keeton, who graduated in 2015 and is an assistant on Andersen's staff, will stand in as the scout team quarterback for the Beavers.