Matt Mitrione believes the Bellator MMA World Grand Prix is "the most exciting thing going on" in mixed martial arts this year -- even if he initially wanted no part of it.

Bellator's eight-man tournament will crown a new heavyweight champion by year's end, but Mitrione admits he was "salty" when first approached with the idea.

That's because Mitrione (12-5) already had an inside track at the title. He's 3-0 in the Bellator cage, including a first-round knockout over Fedor Emelianenko last June. Coming out of that fight, Mitrione believed he was one win away from becoming a champion. Now, he's three wins away.

"I was salty about it. I didn't think it was legit," Mitrione told ESPN's Five Rounds podcast. "I earned that position. Especially with the way I beat Fedor, I earned a title fight.

"I could have sat this out, but why miss a hell of an opportunity? This is not a heavyweight tournament. It's a superfight tournament. It's the most exciting thing going on in our sport -- whether it's UFC or Bellator. This heavyweight tournament is the most exciting thing."

Fighting out of West Lafayette, Indiana, Mitrione faces Roy Nelson (23-14) at Bellator 194 on Friday, in Uncasville, Connecticut.

Friday's matchup is the second leg of the tournament's opening round. Chael Sonnen has already advanced to the semifinals, defeating Quinton "Rampage" Jackson last month.

Mitrione wouldn't go so far as to describe Nelson as his toughest potential matchup but said Bellator certainly didn't give him a free pass. Nelson, 41, holds a previous win over Mitrione -- a first-round knockout in 2012.

"Fighting Roy is an IQ test, that's what it is," Mitrione said. "If you stand in front of him and trade off, you're likely to fail the IQ test. If you fight him mobile and long, the way I fight normally, you're likely to pass that IQ test.

"It's a test of where your mental state is when you're fighting. If you can stay patient and calm, you're likely to do well. If you decide to show how big your balls are, well then, you're rolling the dice buddy."

Roy Nelson is coming off a unanimous decision win against Javy Ayala in September. Dave Mandel-USA TODAY Sports

Mitrione is confident in how much he's improved since his first meeting with Nelson, which was just his seventh professional fight.

So confident, he views himself as one of the best heavyweights in the world. In the current climate of MMA, Mitrione admits that would be an impossible thing to prove, since he can't challenge UFC champion Stipe Miocic, but is holding out hope the landscape could change before the end of his career.

"I think it's a shame to say there's no way, there's not a chance that can be figured out," said Mitrione, asked whether he could prove he's the best of the world in Bellator. "The [Muhammad Ali Boxing Reform Act] looks to be gaining steam and has a chance to pass [to extend to MMA], and if it does, a Bellator champion and UFC champion would have a chance to fight each other. Then you'd actually have an opportunity to prove it, which I find fascinating and good for everybody."