The 49ers on Wednesday placed linebacker Brock Coyle on injured reserve after he sustained a concussion in the team’s season opener.

Coyle, who started 10 games last season, was in the starting lineup for Sunday’s game against the Minnesota Vikings due to Reuben Foster’s suspension and Malcolm Smith’s hamstring injury. He sustained a concussion in the fourth quarter of the 49ers’ 24-16 loss.

The 49ers promoted undrafted rookie guard Najee Toran from the practice squad and also announced the signing of veteran linebacker Terence Garvin to a one-year deal. Garvin will wear No. 57.

The 49ers are thin at guard after foot injuries to starter Mike Person and backup Joshua Garnett. It is unclear whether either player will be available to play Sunday against the Detroit Lions.

The team announced the signing of wide receiver Frank Stephens Northern Colorado) to the team’s practice squad.