The 2011 Heisman Trophy finalist was just a spectator Monday, watching ex-teammate Lavar Edwards and the rest of the Senior Bowl's South team practice. But Mathieu hopes to meet with interested NFL teams during his trip.
Mathieu knows he doesn't have room for more missteps off the field and said he'll understand if team officials react with skepticism.
"They have every right to do that," Mathieu said. "I'm not really looking forward to people trusting me today or tomorrow. Trust takes time, especially when you've done a lot of things for people not to be able to trust you. It may take two years. It may take five years, it may take until I'm 30 years old for people to start trusting Tyrann again. But the truth is, I'm doing the right things and just looking forward to being a football player."
Mathieu was dismissed from the LSU team last August for failing a drug test. He was arrested in late October along with three other former LSU players — including quarterback Jordan Jefferson — after police said they found marijuana at Mathieu's apartment.
He said his NFL ambitions haven't changed even if his days as the "Honey Badger" ended with his college career.
He has been training for the NFL combine in south Florida but was just in Arizona training with Patrick Peterson, a former LSU cornerback now with the Arizona Cardinals.
"I took a few days off from training just to come here and meet with a few coaches and just be back around football again," Mathieu said.
Mathieu, who didn't arrive with any meetings set up, said he knows his behavior will be scrutinized as much as his 40 time.
"This is my last shot," he said. "You've got to learn when to do things and when not to do things, when to party and when not to party. Every day is football. That's the biggest thing I got out of it. I'm just ready to live a football life."
He said his goals haven't changed even though his path to a football career has, and still feels he's a future Pro Bowler.
Mathieu, though, said the past few months have been "really just getting a grip on myself, personally, spiritually and emotionally."
He knows the kids hovering behind a fence calling out "Honey Badger" still think of him by that moniker that became a nationwide sensation.
"I definitely want to do it the right way this time," Mathieu said. "I think in my career at LSU, the Honey Badger kind of just came to an abrupt end. Hopefully, I'm going to give these kids something to look forward to growing up."
However he's known, Mathieu said he had to make changes in lifestyle, starting with the people around him.
Now, he has to convince NFL teams.
"Basically, I just had to take myself out of that situation that I was involved in and get away from all those kinds of people and just really starting hanging myself around positive people, people who are actually doing what I want to do in my life," Mathieu said. "And that's being a professional football player. I think everything's going very well right now. I feel real good about myself. I just try to keep a smile on."
He doesn't smile when talking about eventual national champion Alabama's winning touchdown against the Tigers in November, which essentially knocked LSU out of title contention. It came on a screen pass to T.J. Yeldon when freshman cornerback Jalen Mills blitzed.
"I would have given everything" to be on the field, Mathieu said. "That was a freshman on that blitz and I would have been a junior so I would have known that play was coming. I would have been able to do something.
"It hurts, but it's something that I've got to live with now."