Terrell's injury happened away from the ball -- Cincinnati quarterback Joe Burrow passed to Joe Mixon on the right side. Terrell, defending a receiver on the left side of the field, fell to the ground 15 yards from the play and grabbed his right leg.
The Falcons' doctors and athletic trainers looked at Terrell's right leg before he walked gingerly to the blue medical tent, where he was evaluated and then ruled out. When he came out of the tent, he was still moving gingerly on the sideline.
"We'll just have to see imaging tomorrow," coach Arthur Smith said after the game. "And we'll see where it goes."
Terrell, Atlanta's top cornerback, had left last week's win over San Francisco after he grabbed the back of his right leg, announced later as a thigh injury. At the time, Terrell told ESPN the team was just playing it safe with him, holding him out for the rest of the game against the 49ers so he would be ready to go Sunday against the Bengals.
He practiced all week -- Wednesday on a limited basis and then Thursday fully -- and had no designation on the injury report. This put Atlanta down both of its starting cornerbacks, as Casey Hayward was placed on injured reserve Tuesday because of a shoulder injury requiring surgery that he suffered against the 49ers.
The 24-year-old Terrell has 28 tackles, five passes defended, a forced fumble and fumble recovery this season.
Falcons safety Jaylinn Hawkins left late in the fourth quarter and was evaluated for a concussion. Hawkins said after the game he wasn't allowed to speak with the media, and the Falcons said he was still in the evaluation process for whether Hawkins suffered a concussion on the play.