(Reuters) - The seemingly playoff-bound Cincinnati Bengals suffered a significant setback on Sunday when quarterback Andy Dalton suffered a fractured right thumb in a loss against Pittsburgh.
He was hurt trying to make a tackle after being intercepted during the Bengals' opening drive and was replaced by back-up A.J. McCarron.
Dalton, who has never missed a start during his five-year NFL career, said he did not know how long the fracture would keep him out of action.
"I don't know any details on it. I will be seeing a specialist tomorrow and I'll find out more about it," the quarterback told reporters.
"It's unfortunate it happened at this time ... but I'm going to try to get back as quick as I can."
The Bengals, who were beaten 33-20 by the Steelers, got more bad news when tight end Tyler Eifert was knocked out of the game with a possible concussion after taking a hard hit to the head from Steelers defender Mike Mitchell.
Cincinnati fell to 10-3, two games clear of the Steelers in the AFC North. The Bengals are still in good position to make the playoffs but not yet assured of a spot with three regular-season games remaining.
The Bengals were not the only contending team to have a key player injured on Sunday.
Seattle running back Thomas Rawls suffered a season-ending ankle injury during the Seahawks' 35-6 romp over Baltimore.
Rawls had 44 yards on six carries when he was injured during the first quarter. He has been an outstanding replacement for Marshawn Lynch, who is out indefinitely after hernia surgery.
The surging Seahawks won their fourth game in a row to improve to 8-5, but will have to find a replacement for Rawls, who entered Sunday leading the league in yards per carry.
Reporting by Andrew Both in Cary, North Carolina