With his mentor now retired, Carolina Panthers defensive end Julius Peppers says he's free to be the team leader owner Jerry Richardson asked him to be 15 months ago.

Richardson publicly challenged Peppers in August 2007 to help fill the leadership void left by the retirement of safety Mike Minter.

There wasn't much of a visible response from Peppers last season, when he suffered through the most difficult year of his NFL career (21/2 sacks).

But now, in the midst of a bounce-back season (four sacks in the past five games), Peppers is playing with more enthusiasm and taking a more visible role interacting with teammates.

Peppers said the difference is the retirement last spring of another long-time Panther, defensive end Mike Rucker.

Peppers said he felt he needed to defer last season to Rucker, whom he described as “the guy who when I first came here, I hung on to, tried to learn from, (and) respected him as much as you can respect anybody.”

Their lockers were next to one another and Peppers said he didn't want to upstage Rucker's role on the team.

“I (couldn't) really be myself around him and try to take over – if you want to call it – the ‘Big Dog' role on the defense with him still here,” said Peppers. “I respected him that much. I (didn't) want to step on his toes and try to go over him.

“So, last year, I kind of fell back a little bit and let Ruck do his thing. Now, I feel like I've been here the longest and I feel I can do it a little bit more.”

Teammates have noticed the difference.

“He's a lot more outspoken than he was last year,” said second-year defensive end Charles Johnson.

“He's been talking more this year,” said cornerback Richard Marshall. “Everybody sees it. It shows on the field.”

Peppers remains quiet by nature, but he's playing with a confidence and exuberance that was missing last season.

His four sacks and 12 quarterback pressures roughly match his career averages through the first seven games of a season.

He had perhaps his best game of the season in last week's 30-7 win against New Orleans.

He had a sack, forced a fumble, batted down a pass, and made a key fourth-down stop near the goal line to end a Saints' scoring opportunity.

“I can't get that game out of my mind as far as how he played,” said Arizona coach Ken Whisenhunt, whose Cardinals face Peppers and the Panthers this Sunday at Bank of America Stadium.

“He took over that game.”

Peppers said he valued the play when he caused a fumble more than his sack.

He chased down New Orleans tight end Jeremy Shockey from behind and used his right arm like a sledgehammer to knock the ball loose. Safety Chris Harris recovered at the Saints' 40 and the Panthers went on to score a touchdown four plays later.

“A play like that is way more important than just getting a sack or getting a statistic,” said Peppers.

His disappointing performance last season was probably due at least in part to a preseason illness that sapped his energy and strength.

He said Wednesday he didn't know whether the aftermath of the illness affected him the entire season, but he made it clear he feels much better now.

“That's a fact,” he said. “I am a lot stronger.

“I worked out hard in the offseason, like everybody in here did. The result is you play better on the field. … That's what you're seeing; a whole bunch of hard work in the offseason is paying off.”

Peppers leads a Panthers defense that ranks fifth in the NFL.

They've allowed opponents to score only three touchdowns in the past 19 quarters, a span that includes a 34-0 shutout of Kansas City on Oct.5.

“I'm real comfortable with what we're doing right now,” said Peppers. “I feel like we're getting better. We don't want to get complacent.

“We want to have more shutouts and hold more teams to less yards and less points.”

The Cardinals have the NFL's No.6 ranked offense, led by quarterback Kurt Warner, the league's third-leading passer.

Peppers said there's added motivation to play well against Arizona because the Panthers have the next weekend off.

“You don't want to be sitting at home on a bye week with a loss hanging over your head,” he said.