Trevathan is out for the season, NFL Media Insider Ian Rapoport reported, per a team source, due to a dislocated patellar tendon that will require surgery. The Denver Post's Mike Klis first reported the news.
The 24-year-old was a big part of the Broncos' plans this season, but two separate knee injuries have marred his year. Trevathan has appeared in just three games and compiled 11 tackles.
Rapoport reported that Marshall suffered a mid-foot sprain Sunday, per a source who has spoken to the player. There is no timetable yet for a return, but X-rays were negative.
Marshall has been a quiet stud for the Broncos' front seven this season and the team hopes he'll be back for their postseason run.
The Broncos' defense has been much improved this year thanks to John Elway's offseason additions, but it could be tough trudging through a physical postseason without two of their best linebackers.