Mitchell is a decided long shot to win the heavyweight championship. Brothers Wladimir and Vitali Klitschko hold the four major world titles and have been so dominant that it's virtually impossible to envision them losing any time soon.
But the fact that Mitchell is even in the title conversation is astounding and a testament to his great athletic ability, fortitude, fate and plain good fortune.
Mitchell was a linebacker of some note at Michigan State. If all had gone as he had planned, he'd be chasing down the likes of Adrian Peterson in the NFL.
He led the Big Ten in tackles as a redshirt sophomore in 2003 and was expected to anchor the Spartans' defence the next two years.
Mitchell, though, couldn't stay healthy and had to give up his dream of football stardom.
He didn't play his junior season, his fourth on the East Lansing, Mich., campus, because of a knee injury. Instead of walking away, though, he committed to receiving his degree. He majored in criminal justice with a specialisation in homeland security and security management and was determined to make use of his education.
Mitchell graduated after that fourth year and began polishing up his résumé. That's where fate and good fortune intertwined. He attended the Miguel Cotto-Paulie Malignaggi boxing card at Madison Square Garden in New York on June 10, 2006, as a fan.
On the undercard was a defensive back at Notre Dame, Tom Zbikowski, who had fought in the Golden Gloves and dreamed of having at least one pro fight. Promoter Bob Arum always loved a good gimmick, so he gave Zbikowski a shot in the ring.
That turned out to be the night that Mitchell's heavyweight title dreams were born. Zbikowski, who was drafted by the Baltimore Ravens in '08 and is now with the Indianapolis Colts, went 4-0 in his pro career before walking away from boxing. Having seen Zbikowski fight and win as a pro, Mitchell began to wonder why he couldn't do it as well.
There was a very good reason, actually. Zbikowski had an extensive amateur career, while Mitchell had zero experience as a fighter. Still, it didn't sway him.
"When I saw Tom Zbikowski had success [in boxing], it lit a spark in me and I knew this was what I wanted to do," he said.
Mitchell had a brief, 10-fight amateur career in which he went 9-1 and impressed observers with his raw power and dedication. He's now 25-0-1 with 19 knockouts as a pro and is routinely referred to as America's top heavyweight prospect.
That's damning him with faint praise, to say the least, considering the dearth of quality heavyweights, but the Klitschkos have begun to mention him as a legitimate opponent and it seems inevitable that he'll get a chance.
Given that he'll fight Johnathon Banks, the trainer of Wladimir Klitschko, on Saturday at Boardwalk Hall in Atlantic City in an HBO-televised bout, a title shot may happen sooner rather than later.
Banks took over as Wladimir Klitschko's trainer after the October 25 death of Emanuel Steward, even though Banks remains an active fighter himself. As Mitchell watched Klitschko thrash Mariusz Wach last week, it dawned on him that his bout with Banks might accelerate a match with Klitschko.
"I think a victory over Johnathon Banks will ultimately get me closer to my title shot, whether it's Klitschko or whoever it is," Mitchell said. "… I think I'm looking at first to get Johnathon Banks would definitely increase those chances and Wladimir would probably want to fight me."
It's almost mind-boggling how far Mitchell has travelled in such a short time. Boxing is a sport that requires a lifetime of work to master, in most cases, and Mitchell didn't begin fighting until he was out of college.
It's a tribute to his athletic ability and his personal fortitude that he overcame his football injuries and had a solid, however brief, amateur career.
But to be 25-0-1 and on the verge of a title shot after just six years of boxing is amazing.
He had the advantage of being a superior athlete, but he correctly noted that boxing and football don't always mesh.
"The hardest part of transitioning [from football to boxing] was learning to relax, learning to slow down and to have balance, and just throw punches in combination," Mitchell said. "Nothing is easy from transferring over to boxing."
He said playing middle linebacker helped teach him how to cut off the ring. Filling a hole and chasing down a running back isn't all that different from manoeuvring an opponent into a tight spot and forcing him to fight, with no area of escape.
He's more receptive to coaching and in-ring adjustments, he believes, because of what he's been through as a football player.
"[In] football, you pretty much know what a team is going to do by their formation and things of that nature, so what you're practicing all week and then on Saturday, when you go out there they could line up in their formation and run something totally different," Mitchell said. "And when you go to the sideline, the coach would say, 'Forget everything that we taught you this week; this week, this is what they're doing,' and you have to go over there, have courage, and play it out.
"So I think that's definitely helped me as far as coming over to football. But other than that, boxing is a totally different beast."
Linebackers aren't too often in the spotlight – that's usually saved for the quarterbacks – but the heavyweight champion is always a marked man.
Mitchell is one of the few American fighters who would even be considered for a bout against one of the Klitschko brothers, so almost by default he's one of the country's best hopes of regaining control of what used to be known as the most coveted prize in sports.
He takes the responsibility of representing his country in a bid for the title seriously.
"I never proclaim myself to be the great American hope, the great American heavyweight," Mitchell said. "Honestly, now I just try to work hard, stay humble, stay focused and try to reach my goals. I believe in myself and I believe I have the ability to become heavyweight champion of the world.
"Johnathon Banks, he's standing in my way to achieve that goal, and I'm not taking it lightly. I'm ready to go. But it definitely would mean a lot to me to become heavyweight champion of the world, just to be the best. Whenever I get into something I want to become the best at it, and becoming the heavyweight champion of the world would definitely solidify that."