Senior linebacker Kiko Alonso, Oregon's leading tackler, has not practiced this week while nursing an apparent injury to his left wrist.
It seems unlikely Alonso will be available to play against Colorado on Saturday. With Oregon a 46-point favorite over the Buffaloes, the Ducks should manage without Alonso.
The extent of Alonso's injury is unclear. He has been spotted with a soft cast or wrap around his left hand this week.
If Alonso is unable to play, sophomore Derrick Malone would likely make his second start of the season at one of the middle linebacker spots. Malone started in place of senior Michael Clay against Washington when Clay sat out with a leg injury.
Sophomore tight end Colt Lyerla has also been limited in practice this week, according to a team source, after Lyerla was hit by a helmet in the leg against Arizona State. Lyerla was still limping after practice on Tuesday.