The Ravens will be without starting outside linebacker Paul Kruger for Sunday's game in Philadelphia.
The loss will further test Baltimore's run defense, which was already expecting to have its edge tested by Pro Bowl Philadelphia running back LeSean McCoy.
The Ravens will give more snaps to rookie top pick Courtney Upshaw, who will likely start opposite Albert McClellan. Baltimore has also activated pass-rushing outside linebacker Sergio Kindle.
Kruger suffered a back injury in last week's game and did not practice Wednesday or Thursday. He was limited in practice Friday, and said that it loosened up and felt more comfortable.
Kruger was hoping it would continue to get better in the days leading up to the game, but apparently it didn't improve enough for him to play.
One thing that will help the run defense and pass rush is that Baltimore will have the services of defensive end Pernell McPhee (knee), who was listed as questionable. McPhee shared a half-sack with Upshaw last week against Cincinnati.
All-Pro safety Ed Reed (thigh), who was listed as probable, is also suited up.
Baltimore's other inactives are wide receiver LaQuan Wiliams, cornerback Asa Jackson, guard/tackle Jah Reid, tight end Billy Bajema, defensive end DeAngelo Tyson and defensive tackle Bryan Hall.
The big news on Philadelphia's front is that starting wide receivers DeSean Jackson and Jeremy Maclin are both suited up. Jackson has a hamstring injury that was aggravated this week in practice. Maclin suffered a hip injury last week in Cleveland.
Philadelphia's other inactives are wide receiver Riley Cooper, quarterback Trent Edwards, running back Dion Lewis, cornerback Curtis Marsh, tackle Dennis Kelly, tackle/guard Nate Menkin and defensive end Vinny Curry.