PHILADELPHIA (973espn.com) — Kamu Grugier-Hill has been diagnosed with a significant knee injury.

According to the NFL Network, Grugier-Hill suffered a Grade 3 MCL sprain when tackling Jordan Howard during a live session at Saturday's practice.

A Grade 3 is the most severe type of MCL injury and means the ligament has been completely torn and there is some joint instability.

KGH, who has been having an excellent camp, went down clutching his left knee and trainers checked him out before he was able to gingerly walk off the field where he was loaded onto a cart and taken into the medical tent.

When Grugier-Hill emerged 973espn.com was there and he wanted to join his teammates for the final minutes of the practice before being talked out of it by trainers, instead walking into the NovaCare Complex. Kamu hardly seemed distressed while walking inside and was more concerned about the tape on the hand he injured last season.

Coach Doug Pederson didn't have an update after practice, only confirming that the linebacker had a lower-body injury and more evaluation was needed.

Grugier-Hill has been one of the star's at training camp for the defense, running with the first-team nickel next to Nate Gerry while the team's top LB, Nigel Bradham, continues to work his way back from offseason foot surgery. KGH has intercepted Carson Wentz twice during 7-on-7 drills during camp and had a knock down on a blitz in goal-line work in an earlier live session on Saturday.

“He's really coming into his own,” Pederson said of KGH. “He's obviously getting those first-team reps at linebacker and a core special teams player for us. Really excited about him and what he brings to our football team. He was a young player who's now starting to really grow into his role.”

The initial treatment for most Grade 3 tears focuses on reducing the pain and inflammation while immobilizing the knee to keep it stabilized. Typically a Grade 3 tear takes from four to eight weeks to heal unless it is associated with damage to the ACL.

With Grugier-Hill out of the mix into the regular season that puts more pressure of Gerry as well as backup LBs Zach Brown, L.J. Fort, Paul Worrilow, Alex Singleton and rookie T.J. Edwards.

Worrilow is currently sidelined and listed as week-to-week as he attempts to work his way back from his ACL injury from last spring. The Eagles waived another rookie, Joey Alfieri, on Friday and he was claimed by the New York Giants.

Grugier-Hill, meanwhile, is now the second defender Jim Schwartz will likely be without heading into the regular season. Cornerback Cre'Von LeBlanc suffered a Lisfranc foot sprain earlier in camp.

-John McMullen covers the Eagles and the NFL for 973espn.com. You can reach him at jmcmullen44@gmail.com or on Twitter @JFMcMullen