Oregon quarterback Marcus Mariota briefly left Oregon's game against Washington after taking a hit in the second quarter. Mariota looked a bit gimpy getting up after a hit deep in Washington territory, but stayed in the game and threw a touchdown pass on the next play. The training staff put a sleeve around his left knee, and after walking around fine on the sideline, he went back into the game.
(The Ducks then rolled off a touchdown drive, so this looks to be just an issue to monitor for later on.)
If Mariota gets hit again and needs to leave the game, it would be basically worst-case scenario for the Ducks. He is the engine that drives that team, and has been sensational all season. He's been great so far against the Huskies as well, going 10-12 for 119 yards and a touchdown, and also has 34 rushing yards under his belt. They've already lost top wide receiver Josh Huff with a leg injury, so they can't really stand to lose any other key contributors.
The Ducks are up 21-7 in the second quarter in Seattle, and appear to have a fight on their hands.