GLENDALE, Ariz. (AP) — Entering his fifth NFL season, Tyrann Mathieu is trying to get his confidence back.

Fighting through injuries in all four of his NFL seasons, he has had a hard time maintaining the dynamic "Honey Badger" form best on display two years ago.

Two of his seasons were cut short by reconstructive knee surgery. Last year, a shoulder injury landed him on injured reserve in late December, a premature end to an unsatisfying season for him and his team.

"We know we're an extremely talented football team," Mathieu said. "I know I'm extremely talented personally, but like I said, working on that confidence because last year was a tough one."

Mathieu referred to confidence at least a half-dozen times in a brief meeting with reporters after a training camp practice.

"I feel good, just easing back into it, working back into it," he said, "just gaining that confidence back, which is extremely important for me. Obviously it's a real important camp for me. Expectations are high for myself."

Mathieu, who has 635,000 followers on his Twitter account and legions of fans across the nation, burst onto the NFL scene after being kicked out of LSU for marijuana-related issues and spending a year out of football. Those concerns dropped him to the third round, a steal for the Cardinals in retrospect.

Mathieu emerged as a team leader with absolutely no off-the-field concerns. On the field, he was a menace.

But on Dec. 8 of his rookie season he went down with a severe knee injury, tearing his left ACL and MCL while running back a free kick after a safety.

The rehabilitation was a long one but by 2015 he was back to full strength and at his best.

That year, Mathieu tied for the team lead with five interceptions and led the Cardinals with 16 passes defensed. He made the All-Pro team and was in many ways the spirited heart of the defense, roaming the secondary as Arizona ran away with the NFC West title. But Mathieu wasn't around when that 13-3 season ended with a blowout loss in the NFC championship game

In the 14th game, after intercepting a pass, he went down with another knee injury. This time a torn right ACL. The defense was never the same that season.

Arizona rewarded him before that season with a five-year, $62.5 million contract. He got $21 million on signing and is due another $19 million guaranteed if he's on the team at the start of next season.

He was elected a team captain but the 2016 season that followed the big contract was difficult for Mathieu and the Cardinals. The 5-foot-9 safety thrives on his quickness, instincts and maneuverability. He seemed bothered by the small right knee brace he was required to wear.

Mathieu appeared in 10 games last season, finishing with a career-low 35 tackles, one sack and one interception. Then late in the season, he was on injured reserve again, this time with a shoulder injury.

That 2016 team with such high expectations finished 7-8-1.

"To be honest, I don't think I'm past it," he said of last season. "That's why I'm really harping on that confidence."

Mathieu remains a major part of the organization. He was a high-profile member of a Cardinals delegation to London in advance of the team's game there this season.

And he is practicing without a brace.

"I don't think I'm limited unless you guys know something I don't," he said with a laugh.

But he knows what his contract says. Would the Cardinals stay loyal if an injury strikes again?

"It's a big year for Ty," coach Bruce Arians said. "He's got to stay healthy and get back to being the player we all recognize."

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