TEMPE, Ariz. — The Honey Badger is happy again.

Tyrann Mathieu, the former St. Augustine and LSU standout, is darting around the practice field at organized team activities — no brace on his knee, no cast on his thumb.

“Football is fun again,” the Arizona Cardinals safety said after Tuesday’s workout.

Coach Bruce Arians said Mathieu “looks like a rookie again” — and he meant it as a high compliment.

“He’s got a smile on his face,” Arians said. “He’s extremely quick and fluid again. He’s got his hands on balls. He looks like he was when he was a rookie.”

Two years ago, the Cardinals took a chance after Mathieu missed a year of football following marijuana-related problems that got him kicked out of LSU. The Cardinals got a steal. Mathieu seized the opportunity and for most of the season he was in the discussion for NFL defensive rookie of the year.

Then in Week 14, Mathieu was returning a free kick after a safety against St. Louis when his foot stayed planted in the turf while he was hit by several players. He got up, started to walk off the field and then crumpled to the ground. Mathieu blew a kiss to the crowd as he was carted off the field with a torn left ACL that ended his season.

He wasn’t ready to play when the 2014 season began. He sat out the first game and mostly watched from the sideline for several weeks after that.

Mathieu, encumbered by a knee brace he detested, nonetheless seemed to be making progress when, in Week 13 against Atlanta, he broke his left thumb. Surgery was required to place a pin in it. He missed two games and played the final two with his thumb in a cast. Mathieu was nowhere near the quick, aggressive, instinctive player he had been as a rookie.

“He was playing with one arm and one leg,” Arians said. “He was playing not to lose, and he never played that way.”

Mathieu acknowledged it was a down period.

“Naturally some sort of depression kicks in,” he said. “But for the most part I’d say I had great support, I had great encouragement. And I knew it would come to a day where I’d be healthy again.”

That support group includes the nearly 253,000 who follow him on Twitter, a number that is a tribute to the unquestionable charisma that accompanies his football abilities. It’s a following that seems to baffle him.

“I don’t know. I didn’t really do anything, right?” Mathieu said. “I can’t figure it out, but it’s good, man. Obviously I’ve got a great fan base. Those guys keep me encouraged.”

It was a long, difficult process.

“I would say it took me basically a year to really get back healthy and feel comfortable again (with his knee),” he said, “but I think everybody is different. I’m just happy that I’m finally at the point where I can do a lot of things.”

Now he is back on the field, the guy his teammates recognize so well, the Honey Badger playing — as his coach said — with a “gleam in his eye.”

“He was all over the field today,” defensive end Calais Campbell said. “That’s what made him what he was as a rookie. He was flying around, always in the right place at the right time. ... He’s back to 100 percent.”