The quarterback underwent evaluation for a concussion sustained sometime during the first half — where Washington trailed Minnesota 13-6 — and was eventually ruled out.
Keenum was replaced by 2019 first-round draft pick Dwayne Haskins.
The news of the injury came as a shock to interim head coach Bill Callahan.
Erin Andrews reported just after halftime that Callahan was unaware Keenum was even being evaluated.
He was 12-of-16 passing for 130 yards through the first two quarters.
