Rookie Jarrad Davis was among three Lions starters who missed practice Wednesday as the team began preparations for Sunday's showdown with the defending NFC champion Atlanta Falcons.
Davis suffered a brain injury in Monday's win over the New York Giants and was in the NFL's concussion protocol after the game.
He watched practice from the sideline Wednesday.
If Davis, who's started the last two weeks at middle linebacker, can't play Sunday, the Lions will use Tahir Whitehead or Paul Worrilow in the middle and insert rookie fourth-round pick Jalen Reeves-Maybin into the starting lineup.