Cardinals safety Tyrann Mathieu is finally healthy after a lost season following an ACL tear.

Tyrann Mathieu caused a stir – including one in his own stomach – when his blitz in a recent practice caused quarterback Carson Palmer to get knocked down.

It wasn't ideal, for the Cardinals or for Mathieu, but in some ways, it represented where the safety is these days, blitzing hard off the edge or scrambling over the top of a much taller Larry Fitzgerald to break up a pass.

"He's playing football the way he likes to play," coach Bruce Arians said. "That's how I like to see him play."

That's how Mathieu likes to play too.

A year ago, Mathieu couldn't. He was on the field but he wasn't, sometimes a shell of what he had been as a rookie.When your

game is based on always being around the ball, what happens when you physically can't? When a devastating knee injury steals what made you who you were?

"When you don't make the plays you are used to making, you kind of go in the tank," Mathieu said. "You don't feel right, it doesn't seem right. I'm just happy that I'm finally healthy and I have my confidence back."

Mathieu is the flip side of the Carson Palmer ACL success story. Palmer, whose knee injury was not as severe as Mathieu's, was cleared to play well before training camp. Mathieu started last year's camp on the Physically Unable to Perform list, and while he was technically active by the time the regular season started, he was not the Honey Badger that sparkled as a rookie.

It's one thing to be able to play. It's another to be able to play well.

Now, "he looks like he is back to being himself," Arians said.

Mathieu admitted he didn't feel completely healthy until after the 2014 season ended. Mentally he was able to approach his rehab with impressive maturity, perhaps not a surprise for a guy who had nearly lost football because of his marijuana problem in college.

That recovery remains his priority – "I'm still on that journey" – but he had to work at staying upbeat working through last season.

"I try to stay positive," Mathieu said. "I remember those dark times (in college.) I know what type of person I am. If I tell

myself something enough, I'll believe it."

It wasn't as if Mathieu was bad last season, when he was able to get on the field. He just wasn't, well, Mathieu. He wasn't the guy near the tipped passes, he wasn't as effective on the blitz. Whether it was the mental or physical hurdle – or both – of coming off such a horrible injury, it was noticed.

Combine it with the inconsistent play of cornerback Patrick Peterson, and as well as the defense played in 2014 there was a feeling much was missing.  

"We are the cornerstone on the defense for playmaking," Peterson said. "Everyone has the ability but all eyes are on us to make plays. We are kind of the sparkplugs."

That's a description Mathieu embraces. It's hard to believe given where he was in college, but Mathieu has emerged as a leader. Not a talker, Mathieu's game speaks volumes for where the Cardinals' defense can go.

"He's not a vocal guy but he plays loud," Arians said.

And that's exactly Mathieu's point, after being muted a year ago.

"I know if I'm on the field and healthy I'm going to make plays," Mathieu said. "I'm pretty confident in that."