49ers linebacker Dre Greenlaw has missed the past two practices.
Coach Kyle Shanahan revealed Monday that Greenlaw is in concussion protocol.
The 49ers placed linebacker Fred Warner on the COVID-19 list. The absences of Greenlaw and Warner will give the team’s depth linebackers more snaps in the interim.
Offensive tackle Trent Williams received a veteran’s day off Monday.
The 49ers expect tight end George Kittle to return later this week. He has not practiced since last Wednesday because of hamstring tightness.