The 49ers announced they have placed linebacker Brock Coyle on injured reserve. Coyle broke a bone in his back -- a C4 compression fracture -- and will need at least six weeks of recovery, Matt Barrows of The Athletic reports.
The team previously announced Coyle was diagnosed with a concussion.
The 49ers signed linebacker Terence Garvin to a one-year deal and promoted offensive lineman Najee Toran from the practice squad.
San Francisco had a need for a guard after starting right guard Mike Person (foot) and his backup, Joshua Garnett (dislocated toe), were injured in Sunday’s loss. The 49ers moved rookie Mike McGlinchey from right tackle to guard during his pro debut.
Garvin originally entered the NFL after signing with the Steelers as an undrafted rookie free agent in 2013. He has appeared in 74 career games, with four start, and made 27 tackles, 1.5 sacks, one pass defensed and one forced fumble along with 49 tackles on special teams with Pittsburgh (2013-15), Washington (2016) and Seattle (2017).