SANTA CLARA – Outside linebacker Ahmad Brooks, who ranks second on the 49ers with four sacks this season, will not suit up for the team’s game Sunday against the Arizona Cardinals at Levi's Stadium.
Brooks, who reported back to work after the Seattle Seahawks with a headache, was placed into the NFL’s concussion protocol. He did not receive final medical clearance to appear in Sunday’s game.
The 49ers are expected to start Corey Lemonier at Brooks’ position. Rookie Eli Harold is also expected to see playing time. The team’s sack leader, Aaron Lynch, lines up on the other side.