Atlanta ruled Daniels out for the rest of the game. The team's statement did not provide a further diagnosis or a timetable for his return.
Daniels, a fourth-round pick from Oklahoma, has started since Week 1. He was handling the defensive play-calling duties when he was injured, according to ESPN. Josh Woods took over that responsibility after Daniels left.
The Falcons were also without linebacker Divine Deablo, who had been ruled out with an arm injury, the NFL's official injury update reported.
Players and coaches gathered around Daniels as the medical staff prepared to move him. ESPN reported that he made a fist with his left hand as the cart carried him away. The Falcons' subsequent update confirmed he was alert and had movement while hospital staff continued evaluating him.