The Eagles defense will be missing at least one likely starter when they open the regular-season on September 8 against Washington.

The team confirmed Sunday before their evening practice at Lincoln Financial Field that linebacker Kamu Grugier-Hill will be out “multiple weeks" with what the Inquirer reported Saturday is a Grade 3 MCL sprain.

Grugier-Hill suffered the injury Saturday in a "live-tackling" session in practice.

“It hurts to lose Kamu for even the little bit of time that we’ll miss him," defensive coordinator Jim Schwartz said before practice Sunday. “He was having a good camp. Third year in the scheme. Was developing and showing a mastery of what we’re doing. So it’s a little bit of a setback for him and for us.

“The good news is we’ll get him back eventually."

When that will be at this point is uncertain. Grade 3 MCL sprains can take up to three months to heal.

The Eagles have several other key defensive players who are coming off major injuries and have yet to participate in team drills. They include defensive tackle Fletcher Cox (foot), cornerbacks Ronald Darby (ACL) and Jalen Mills (foot), defensive end Derek Barnett (shoulder) and linebacker Nigel Bradham (torn ligaments big toe).

But the only one who may not be ready for the start of the season is Mills, who is on the team’s physically unable to perform list.

Grugier-Hill, who also is the Eagles’ special teams captain, was having a solid camp. He started 10 games last season and was expected to start in their base defense this season, as well as some of their two-linebacker sub-packages. But Schwartz has options there.

“That’s probably one position where, if you’re watching, you see so many different groups of guys" getting reps in practice, he said.

“Obviously, with Nigel not practicing right now, it provides a lot of opportunities for guys. But we have guys who were here last year. We signed some rookies. And we even brought in some vets like L.J. (Fort) and Zach (Brown).

“All of those guys have done good things. The biggest thing will be, at the end of camp, at the end of our preseason games, trying to figure out who fits best where and who can handle the role that’s required of them."

Nate Gerry, a 2017 fifth-round pick, played 134 defensive snaps last season and started two games. He started in place of the suspended Bradham in Week 1, then filled in for Jordan Hicks when he missed four games in the second half of the season.

“We won some important games down the stretch with Nate Gerry as a starting linebacker for us," Schwartz said. “So we’re certainly confident in putting him in the game, and he has confidence in himself. The one thing about him is you know he’ll be ready.

“We haven’t paid that much of a price for having him on the field. He’s helped us win and he’s made some big plays. He was a key part in winning some of those games down the stretch that helped us make the playoffs."

Brown replaces Brown

In a related move Sunday, the Eagles signed linebacker Asantay Brown and released cornerback Alex Brown.

Asantay Brown was originally signed by the Eagles last year as an undrafted free agent out of Western Michigan. The 6-0, 215-pounder was cut before the start of the season and spent most of the year on the team’s practice squad. He signed a reserve/futures contract after the season, but was released in May.

Going public

Sunday night’s practice was the Eagles’ one-and-only, open-to-the-public training camp workout. The rest of their workouts are at the NovaCare Complex, where only selected season-ticket holders, VIPs and sponsors can watch.

Schwartz said the trip across the street to the Linc was a good break for his players.

“It gives us a nice lift during the dog days of training camp," he said. “Players get to come out here, particularly the young players who’ve never experienced it, and see where their locker would be, and go out there and just experience the crowd.

“It’s even good for testing your communication. We have music at practice, but guys can talk over the music. It’s hard to talk over the 40,000 or whatever we’ll have tonight."