GREEN BAY – The Packers defense knows what it’s going to get on Sunday.

“We just have to brace for the run game,” linebacker Clay Matthews said on Thursday. “They’re undefeated for a reason. They’re doing it the right way, having success running the ball.

“We have to stop the run early, and we know they’re going to be committed to it.”

The Panthers are likely to stay committed to it because they’re the top-ranked rushing offense in the league, and the Packers put plenty of struggles against the run on film last week in Denver.

That combination makes this a four-quarter, stop-the-run game. Carolina’s Jonathan Stewart (pictured) has cracked the 500-yard plateau through seven games, and quarterback Cam Newton has added roughly 40 rushing yards per contest.

It’s also not just how often the Panthers run the ball – 233 of their 462 snaps, or almost precisely 50 percent, are rushes this year – but how many different ways they run it. In addition to Stewart’s workload and Newton’s contributions, receiver Ted Ginn, Jr., has a 43-yard run this season, and another receiver, Philly Brown, has added 41 yards on four attempts. Even fullback Mike Tolbert has 20 rushes this season for an impressive 4.6 average.

“They do it all,” linebacker Julius Peppers said. “They have great runners. The offensive line plays well together. They play hard; scrappy group. They do it all, inside and outside.”

The Packers need their run defense from earlier this season to show up on Sunday in Charlotte. The unit has been up and down all year.

The Bears rolled up 189 rushing yards in Week 1, but then the Packers shut down a series of feature backs in Seattle’s Marshawn Lynch, Kansas City’s Jamaal Charles and San Francisco’s Carlos Hyde, who combined for just 110 yards in Weeks 2-4.

St. Louis kept pounding away with Todd Gurley despite falling behind early, and the rookie rushed for 159, before San Diego gave up on the run and then Denver gashed the Packers for 160, including five runs of 15-plus.

“It’s a lot,” Peppers said of what’s gone wrong on the bad days. “There’s levels to it. It’s the defense that’s called, it’s the execution of the defense, it’s gap control. I can’t necessarily say it’s one thing or the other. We just have to do a better job of playing our responsibilities.”

One tough responsibility will be tackling Newton, whether he’s in or out of the pocket, or running the option or QB draw.

Safety Morgan Burnett knows all about Newton, having grown up with him in Georgia. On youth teams, Burnett was the QB and Newton was his fullback, the kind of kid who was so large for his age that parents complained about his dominance. Handing off to Newton on a fullback dive was Burnett’s favorite play.

“He was bigger than all the other kids, so nobody could tackle him,” Burnett said. “He’s still big.”

At 6-5, 245, Newton is probably the toughest to tackle of all the mobile QBs the Packers have faced, a group including Seattle’s Russell Wilson and San Francisco’s Colin Kaepernick.

“You look even when linebackers are tackling him he’s falling forward for a few extra yards,” Matthews said. “He does some things that I don’t think many coordinators are comfortable with their starting quarterback doing, as far as the hits he takes. You wouldn’t see us doing that with 12 around here.”

A healthy Matthews would help the Packers’ cause on defense, especially with cornerbacks Sam Shields and Quinten Rollins (both shoulder injuries) yet to practice this week.

Matthews’ ankle injury from the Denver game has limited him in practice, but he said he’s pleased with its progress and is hoping “come Sunday it won’t be too much of an issue.”

Receiver Ty Montgomery also is dealing with an ankle injury that sidelined him in Denver. He has been limited in practice, though Head Coach Mike McCarthy said his workload was increased Thursday. Montgomery said he’s taking things “day by day.”

That’s the approach the Packers have taken all week in moving on from their first loss and getting ready for another undefeated foe. There were lessons to learn from Denver, but the focus is fully on Carolina now, as it should be.

“At the end of the day, whether you do good or bad, in this league it’s all about what are you doing now?” Burnett said. “What are you going to do next?”

For the defense, stop the run is first on the list.

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