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. Lynch has six sacks on the season.

In pass-rush situations, the 49ers could use Tank Carradine, who has dropped weight as the 49ers plan to employ him more as an outside pass-rusher. Ray-Ray Armstrong, whom the 49ers claimed off waivers from the Raiders, is not active.

Cardinals will have safety Deone Bucannon who is returning from a concussion, and cornerback Patrick Peterson (ankle). Both players were listed as questionable of the team’s injury report.

49ers inactives
WR DeAndrew White
RB Carlos Hyde (foot)
CB Chris Davis
OLB Ahmad Brooks (concussion)
OLB Ray-Ray Armstrong
G Brandon Thomas
G Ian Silberman

Cardinals inactives
QB Matt Barkley
LB Shaq Riddick
G Jonathan Cooper (knee)
T D.J. Humphries
DT Cory Redding (ankle)
DT Ed Stinson (groin)
DT Frostee Rucker (ankle)