Head coach Mark Helfrich played it coy, saying he "[could] neither confirm or deny anything," following that up by saying Addison was at Friday's practice.
Teammate and friend Keanon Lowe was more responsive to questions from reporters.
"Just first and foremost as his friend, it's tough to see that. That's an athlete's worst nightmare," Lowe said.
While Oregon will not comment on the specifics of the injury, CSNNW.com's Aaron Fentress reported last night that it was indeed a torn ACL and that Addison "could miss the entire 2014 season."
Lowe said it took himself a second to refocus after watching Addison go down, but that they must step up in his absence.
"There's a lot of opportunities for other guys to step up, and that's how you have to approach it," he said.
Addison is the top returning receiver and punt returner from 2013, and had figured to take on an even more expanded role this fall.
Without him the Ducks are forced to regroup and reconfigure their passing attack. Offensive coordinator Scott Frost acknowledged the challenges of doing so, but said they've still got plenty of weapons.
"First of all, I love Bralon," he said. "He's going to make a hell of a lot more plays before he's out of here, but we have a lot of other guys on scholarship and a great quarterback to throw to him."
Frost was asked who he had seen step up and gave the following comment:
"We're waiting on B.J. Kelley to be the guy we expect him to be. Devon Allen had a good day today. Jalen has a good chance. He should still be in high school, but he's done a great job of picking things up and going forward. Chance and Dwayne are improving and have a chance to really help us. Keanon Lowe is the leader of the group. Johnny Loyd's shown some flashes. We have a lot of running backs we can put in different spots too."
And what about the possibility of Addison returning for 2014?
Frost said that would be up to Addison, and that the team was on his side no matter what.