Jon Gruden is impressed.

Gruden, the Tampa Bay coach, has watched plenty of Carolina Panthers tape as he prepares his Buccaneers for their big NFC South Division contest on Sunday in Tampa, and he thinks he's seeing something special, particularly in a Panthers defense that ranks second in the conference, allowing an average of 254.5 yards a game.

“I'll tell you this; they're all over the place,” Gruden said on a conference call with Carolinas media. “They are playing their butts off. That's a credit to those players and coaches; they are playing their hearts out.”

So why is this Carolina defense performing so much better than last year's unit, which allowed a 324.8 average in the team's 7-9 season?

Gruden starts with middle linebacker Jon Beason, who took over the position last season as a rookie.

“Beason is a Pro Bowl linebacker right now if you ask me,” he said. “He's their heart and soul. He's flying around and they have great speed at linebacker. It starts right there – (Thomas) Davis, (Na'il) Diggs – those guys can run.”

Then Gruden added four simple words: “And Julius is back.”

Meaning defensive end Julius Peppers. After three straight seasons of more than 10 sacks, Peppers inexplicably dropped to 2.5 last season, and often seemed listless. This year, he's the old Peppers, a force with three sacks through five games.

“He is an upper-echelon player in the world, and he brings a lot to the Panthers,” Gruden said.

“And they've got great coverage ability there. I think those three corners (Ken Lucas, Chris Gamble and Richard Marshall) stack up against any other three in football.”

Gruden is also impressed with the increased aggressiveness of Carolina's defense. In addition to moving Peppers from left defensive end back to the right side where he is more comfortable, they moved Davis from strongside linebacker to the weak side, giving him more opportunity to create havoc in the backfield.

And safety Chris Harris, who was up and down last year in his first Panthers' season, has developed consistency to go with his pad-crunching hitting.

Also, the defense has been simplified a bit, allowing players to react more rather than think too much.

Gruden isn't the only one who has seen the change.

“We simplified it to a certain extent, and our coaches are doing a good job of game-planning teams, putting in some new blitzes,” said Beason. “For the most part, guys have really bought in and are giving it their all.”

A fact not lost on Carolina's offense.

“They're fearless,” said Panthers guard Travelle Wharton.

“In practice going against those guys, they're out there and playing and having fun. And that's the main thing; you can see them smiling and having fun and challenging each other. They're moving full speed.”

Which brings us back to Gruden.

“It's their style,” Gruden said. “They are aggressive, man. They blitz on every front. Unorthodox, reckless blitzing. They hammer you with blitzes, they play a disciplined zone, and they all can run and hit.”

Much like Tampa Bay's defense in most seasons. Defensive coordinator Monte Kiffin's units usually rank in the NFL's top 10, but this one is in the middle of the pack so far, ranked 16th of 32 teams because it has allowed 318.2 yards a game. Expect that to change; the Bucs' defenses have lived in the league's top 10 in 10 of the past 11 seasons.

It's a level that Carolina aspires to.

“I think there are some similarities,” Gruden said of the two teams. “Not in the plays that we run, but in philosophy. Just hard-nosed, tough defense. A running game. A physical mindset. That brings out the best in these teams, I think.”