49ers' Nick Martin: Won't play vs. Titans

Martin (concussion) is out for Sunday's game versus Tennessee, Cam Inman of The San Jose Mercury News reports.

Martin sustained a concussion in Week 13 at Cleveland prior to San Francisco's Week 14 bye, and now he'll be sidelined for Week 15 as he continues to recover. His absence could mean more reps at linebacker for veteran Luke Gifford.