Safety DeMarcco Hellams was injured on the second defensive play of the night for the Falcons in a preseason game against the Dolphins.
Hellams had an air cast placed on his lower left leg before he was loaded onto a cart and taken to the X-ray room.
He was competing with Richie Grant for the starting strong safety spot opposite Pro Bowl free safety Jessie Bates III.
Hellams, a seventh-round pick in 2023, played 15 games with four starts last season as a rookie and made 40 tackles.
The Falcons lost receiver Rondale Moore for the season on Wednesday when he injured his knee during a joint practice against the Dolphins.