Muse (knee) was placed on injured reserve Tuesday, Tom Pelissero of NFL Network reports.
Head coach Brandon Staley told reporters Monday that the 27-year-old linebacker would likely head to IR after suffering a knee injury during Los Angeles' Week 11 loss, so this move doesn't come as a surprise. Muse had appeared in all 10 of the Chargers' games thus far, logging two total tackles and playing strictly on special teams.