Quarterback AJ McCarron makes his first career start for the Cincinnati Bengals as they try to clinch the AFC North and a fifth straight postseason berth against the San Francisco 49ers.
He is filling in after Andy Dalton broke his right thumb in last week's loss to the Steelers.
But McCarron won't have a top target as tight end Tyler Eifert - with his 12 touchdowns - is out with a concussion.
Wide receiver Torrey Smith, who dealt with back spasms and a toe injury, is active for San Francisco against the Bengals.