"I'm sitting in that jail cell thinking, 'I don't know if I want to go back out there and face the music,'" he told Fox Sports Arizona. "I didn't know how I was going to commit suicide in the cell, but that was the direction my life was heading."
The second-year safety let the social media world know about his thoughts by changing his Twitter profile to say: "I've tried committing suicide. But I didn't, look at me now." He's since changed his profile.
Mathieu, who's out recovering from a torn ACL and LCL, told Fox Sports Arizona that his cellmates talked him out of suicide by "telling me I was a good football player, telling me I don't need to be thinking about this."
"That's probably why I really didn't do it, but there was an actual moment where I was thinking about, and I'll never forget that feeling," Mathieu said.
Mathieu was arrested Oct. 25, 2012, along with three other Louisiana State football players after police found marijuana in his Baton Rouge, La., apartment. It ultimately was the breaking point for Mathieu's career at LSU, which had ended in August of that year when he was suspended from the team indefinitely by head coach Les Miles for failing multiple drug tests.
Known as the Honey Badger for his performance on the field, Mathieu isn't hiding from that day. He wants others to learn from him.
"I think the biggest thing is to be open about it," he said. "Part of it is reaching out to others trying to help; part of it is self-counseling, talking about it, not shying away from it. Most people try to isolate themselves and pretend like things are all good when a lot of times, that's not how it is."