CSNNW's Aaron Fentress has confirmed our fears:
Unfortunately, this was always the likely scenario once we heard that Addison suffered a non-contact knee injury. Apparently, he went to cut, his knee gave and he fell down.
The first though should be with Addison and his recovery. Fortunately, he is at a place where he will get the best care in the world, and we should expect Addison to come back strong in 2015.
It does leave a hole in the Oregon wide receiver rotation, where Addison was the key returning cog. Josh Huff, Daryle Hawkins, and DeAnthony Thomas also left either for graduation or the NFL Draft, while starter Keanon Lowe returns. Fortunately, Oregon has a ton of wide receivers on the roster, but Addison was the best proven playmaker on the team.