Mathieu faced a different kind of personal challenge in college. He got kicked off LSU's football team for failing multiple drug tests, then found himself in jail after police searched his apartment and found marijuana in 2012.
Mathieu acknowledges he had suicidal thoughts at the time.
"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 said Tuesday, via 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."
He received words of encouragement from an unlikely source.
"Believe it or not, my cellmates were encouraging me, telling me I was a good football player; telling me I don't need to be thinking about this," Mathieu said. "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 he plans to start a foundation to help others who have had similar thoughts in times of struggle.
"People go through a lot of things. They can be every-day personal things, not just suicide," he said. "I just want to reach out and use this platform for something positive and be an inspiration to people who want to see me as an inspiration."
Mathieu's is a nice story: a high-risk draft pick by the Cardinals who seems to have turned his life around. He wants to be a role model, which is quite a turn from where he was not long ago.