GREEN BAY, Wis. -- Clay Matthews has now missed more practices (four) this training camp than he has taken part in (three).
And that gap is expected to widen because the Green Bay Packers linebacker doesn't know when his sore knee will allow him to return.
Although he continues to insist it's nothing serious, Matthews is not sure if he'll be back for the preseason opener next Thursday at New England.
"Hopefully, I'll be back sometime next week for that Patriots game, but I don't know," Matthews said after Friday's practice. "Sometimes my mind and body don't align with each other, but we'll see. Like I told some of you guys before, it's nothing to worry about, nothing too serious, and hopefully will be back very shortly."
Neither Matthews nor coach Mike McCarthy believe the absence will slow his growth at inside linebacker. This is the first training camp for Matthews in his dual role after adding those duties midway through last season.
"I think the biggest and most important thing that Clay needed was really just to start from the beginning at the position," McCarthy said. "You go back to Square 1, learn everything from the progression of teaching -- his run fits, his pass responsibilities, his pressure responsibilities -- get to practice them throughout the whole offseason, go through an install of the whole defense through the offseason and now this is really the review for the veteran players because there's nothing that we've done in the spring that we're not doing now."
Here are other notes from Friday's session:
Linebacker shortage: The Packers are running short on outside linebackers. Not only is Matthews out, but so are Mike Neal (abdomen), Nick Perry (groin) and Adrian Hubbard (groin). Neal has yet to practice and remains on PUP. Also, Jayrone Elliott dropped out midway through practice because of a shoulder injury.
Injury of the year:: Some years, it's knees. Other years, it's hamstring. It seems to be groins this year. In addition to Perry and Hubbard, first-round pick Damarious Randall and defensive tackle Mike Pennel are dealing with the same injury. "Groins and strains are the fatigue injury category," McCarthy said. "This is where you have to really watch yourself."
Early release: Those fatigue injuries played a part in why McCarthy cut practice short. At one hour and 36 minutes, it was by far the shortest of the seven camp practices. A wet field from a light rain that fell during practice also was a factor. "We had planned on cutting practice shorter than the previous practices," McCarthy said. "This is frankly the point in camp when you get to eight, nine, 10 practices in, this is the threshold in where you have to be smart with trying to prevent the fatigue injuries. It was a little slick out there with the light rain."
Crockett returns: Rookie free-agent running back John Crockett finally passed his physical and was taken off the PUP list. He practiced for the first time on a limited basis. He did only individual drills but soon should get into the mix for the No. 3 halfback job (if they keep three) with Rajion Neal and Alonzo Harris.