ALLEN PARK -- Detroit Lions linebacker Jarrad Davis has missed a second straight day of practice, and it's looking increasingly likely he'll be unavailable for Sunday's game against Atlanta.

Davis suffered a brain injury in the second half of Monday's win against New York. He's attended both practices this week, but participated in neither. Detroit will practice once more, on Friday, before hosting the unbeaten Falcons at Ford Field.

Tahir Whitehead is expected to replace him at middle linebacker if he's unable to go, wile rookie Jalen Reeves-Maybin would slide into the weak-side job usually occupied by Whitehead.

Both Whitehead and Reeves-Maybin have declined all interview requests this week. Davis has been unavailable for comment while in the concussion protocol.

Two other starters, center Travis Swanson and safety Tavon Wilson, also missed their second straight day of work. And reserve running back Dwayne Washington sat as well with a quad injury.

Zach Zenner is looking like a good bet to make his debut in Washington's place on Sunday. He led Detroit with four rushing touchdowns last year, but has yet to be active for a game in 2017.