GREEN BAY – Clay Matthews wants Packer Nation to rest easy.

"I wouldn't worry about me," Matthews said after missing his fourth straight practice Friday with a sore knee. "I'll be back shortly and hopefully get back to making some plays."

Matthews termed the rest precautionary, and though he said it's never ideal to miss practice, especially while learning a new position at inside linebacker, he's not at all concerned about being ready for the season.

He pointed out that he has missed chunks of training camp in the past and been no worse off. Back in 2010, he didn't play in any preseason games due to a hamstring injury and then responded with back-to-back three-sack games in the first two weeks of the regular season.

He also took the field at inside linebacker for the first time last year after just four practices, right after the bye week, whereas this year he had the entire offseason to get up to speed at the new spot.

That more than anything has eased any potential anxiety for Head Coach Mike McCarthy over Matthews' early absences from camp.

"I'm not of high concern," McCarthy said. "The biggest and most important thing Clay needed was to start from the beginning at the position, go back to square one, and learn everything."

Matthews described himself as comfortable mentally in that regard. To him, the physical setback now is a bit ironic considering he felt better than he ever has this past offseason, but he's reassuring anyone who asks that the sore knee is "nothing serious."

"I'll get back out there," he said. "I'll be fine. I always am. Hopefully it's not too much longer."

Nate Palmer and rookie Jake Ryan have continued to rotate daily as Sam Barrington's companion at inside linebacker with Matthews out. If nothing else, their progress has probably been accelerated to this point.

The defense as a whole appeared to take a step forward on Friday, getting the best of the offense in one particular series of goal-line plays.

Veteran defensive lineman Mike Daniels said he likes the energy the unit is playing with, and he's encouraged by what he's seen from some of the defense's younger players. Friday was a building-block kind of day heading into Saturday's
Family Night workout at Lambeau Field.

"Absolutely. We go against the best in the league up front," Daniels said. "The best quarterback in the league, the best offensive linemen in the league, and one of the toughest running backs in the NFL. It's going to be a challenge every day, and we accept the challenge. It only makes us better."

Some of the battles in one-on-one and half-line drills between Daniels and guards Josh Sitton and T.J. Lang, and between B.J. Raji and center Corey Linsley, have been entertaining to watch.

Those could go a long way toward helping a defensive line that will be shorthanded come Week 1 due to the suspensions of Datone Jones and Letroy Guion (whose appeal is pending).

"I really like the intensity and I like the way guys are finishing and flying to the ball," safety Morgan Burnett said. "That's what makes it fun and what defense is all about. That's the most exciting thing to see, when you turn on the film, you see how fast guys are moving and trying to get to the football."

Aaron Rodgers produced his share of touchdowns in the red-zone and goal-line work once the No. 1 offense found its footing, but the defensive backs were still getting their hands on a number of passes from the other QBs.

Casey Hayward perfectly undercut Jeff Janis' route in the back of the end zone and should have intercepted Matt Blanchard's throw, but it bounced off Hayward's chest. Moments later, rookie Damarious Randall broke up an end-zone throw from Brett Hundley to Larry Pinkard.

Even Palmer got in on the act, batting down a Scott Tolzien pass near the pylon with his clubbed-up hand, a play that drew a fist bump from McCarthy.

"I think we're just locked in as a unit," Hayward said. "We know in the back end, we're going to have to play huge in order for this defense to be an elite defense."