Cardinals defensive tackle Calais Campbell gives advice to rookie Robert Nkemdiche at Thursday's practice.

Carson Palmer considered the question about who the loudest Cardinal was in the locker room.

The quarterback mentioned defensive tackle Calais Campbell, "but in a different way."

"He's just always coaching and always talking, but not about himself, ever," Palmer said.

Campbell never has been self-promoter. There were years when he played well enough to earn Pro Bowl consideration but didn't make it, and Campbell wouldn't complain. When coach Bruce Arians noted last year that Campbell needed to

dominate more often, Campbell simply agreed with the sentiment.

And now, after back-to-back Pro Bowl appearances, Campbell is being low-key about a contract that's about to run out after the 2016 season, which would make him a free agent.

"You hire an agent so you don't have to worry about it, an agent that you feel will do a great job for you and positon of power and you go concentrate on football stuff," said Campbell, who hired Tom Condon this summer after his first agent, Ben Dogra, was suspended. "I let him go to work and I don't worry about it anymore. I just play football as hard as I can, like I always do."

Effort has never been questioned with Campbell. But Arians continues to say he believes Campbell can do so much more.

"I expect a dominating player every week, which he is capable of being, especially with the guys around him, with Corey (Peters) back and Chandler (Jones) and Frostee (Rucker) in the mix and everyone else," Arians said. "I expect a dominating player who shows up in the stat sheet every week. Big."

While Campbell had 51 tackles last year, a number he has consistently and impressively put up despite playing inside, his sack total fell to five – his lowest number since a rookie season in 2008 when Campbell went sack-less. He also knocked down just two passes, his lowest total since 2010.

That figures to change this year with the addition of Jones, who frequently will line up near Campbell and give teams problems.

"The good players -- the great players -- they always want to be better," Campbell said. "You're never going to be

satisfied. I feel like my game is always evolving. I am always learning new ways to do things, better ways to do things. I feel explosive, I feel strong. The biggest difference is mental. Every year you just feel a little wiser."

That's why Campbell is leaned on for leadership. At one point during Thursday's practice, Campbell had a short talk with rookie Robert Nkemdiche after a play, correcting a mistake. Frequently, fellow defensive tackle Josh Mauro can be seen talking to Campbell, learning what he can.

"He's a leader in the stuff that doesn't get talked about," Mauro said. "He doesn't miss practices, he doesn't miss meetings, in the offseason when guys are traveling he's at most everything. He does it the right way. He just doesn't sit there and talk about it and just show up on game day."

How long that carries into the future is in question. Campbell will make $9.5 million in salary and has a cap number of more than $15 million in the final year of his contract. He will be 30 on Sept. 1. No. 1 draft pick Nkemdiche is a similar player.

Campbell knows the contract questions will be ongoing. But he smiles and shrugs it off. As a rookie, Campbell reached the Super Bowl, and all he's thinking about is this season and getting back there.

"This team is special and we have a lot of possibilities to be really good," Campbell said. "My mindset is I just don't want to let anyone slack off and we work really hard. That's my number one goal, to make sure I'm pushing everyone to be the best they can be."