ALLEN PARK -- Detroit Lions linebacker Jarrad Davis is not expected to play Sunday against the Atlanta Falcons because of a brain injury.

Davis suffered the injury in Monday night's win against the Giants and hasn't practiced all week. That includes on Friday, as Detroit wrapped up its final full practice of the week.

According to a team doctor, the final hurdle to clear the concussion protocol is to practice with contact. And Detroit's only workout left before the game is a light walk-through Saturday morning.

The Lions will issue their official game designations at 4 p.m.

Here's a quick snapshot of the concussion protocol, per a team doctor:

Step 1: Become symptom-free

Step 2: Begin light exercise

Step 3: Go 100 percent for a cardio workout

Step 4: Practice without contact

Step 5: Practice with contact

Final step: Independent neurologist grants approval to return

Here's a more thorough look at the protocol:

Davis has attended every practice this week, despite a bright sun splashing the field all three days, which indicates he shouldn't be out for the long term. But it appears he won't have enough time to return for the showdown against Atlanta's high-octane offense.

Center Travis Swanson (ankle), safety Tavon Wilson (shoulder) and running back Dwayne Washington (quad) also missed the full practice week. Graham Glasgow is expected to move from guard to center if Swanson can't go, while Miles Killebrew and Charles Washington are the leading contenders to replace Wilson.

Zach Zenner, inactive the first two weeks of the season, could dress for the first time in 2017 if Washington is out as expected.