The UFC hits Little Caesars Arena in Detroit this weekend for a UFC 218 pay-per-view event.
Original plans called for a featherweight title fight between Max Holloway and Frankie Edgar, but Edgar was forced to pull out due to injury.
In steps former champ Jose Aldo, who lost the title to Holloway five months ago. The Brazilian great will attempt to make the most of an immediate rematch, which he felt he deserved anyway.
In the co-main event, veteran heavyweight Alistair Overeem will try to solidify a future title shot as he takes on rising contender Francis Ngannou.
ESPN's Cheat Sheets are here to break down Saturday's storylines and predict the winner for this UFC 218 fight.
Alistair Overeem (43-15) vs. Francis Ngannou (10-1), heavyweight
Odds: Ngannou -270; Overeem +230
Saturday's co-main event is one of the most anticipated heavyweight fights of the year -- and, apparently, the UFC is already formulating plans for the winner.
The matchup certainly looks like a No. 1 contender fight on paper, and with defending champion Stipe Miocic expected to return early next year, the winner might be looking at a quick turnaround.
"They actually have told me they want the winner to fight for the belt," said Overeem, regarding communications with UFC executives. "Rather soon, if I'm not mistaken. I'm not going to say a date, but it's very soon.
"My reaction was whatever. I'm focused on the hurdle in front of me. A quick turnaround would depend on health, how I feel after this fight. So there's no sense to talk about it now."
Ngannou, who had a fight fall through in September and hasn't fought in 10 months, also said a quick turnaround would depend primarily on health.
"I'm ready," Ngannou said. "I've been out a long time so now I'm ready. If I get through this fight without injury, I will be ready to step in. It doesn't matter how long -- maybe weeks."
A heavyweight title shot is obvious motivation for both -- although, listening to each of them, it's clear they are self-motivated heavyweights.
For Overeem, 37, Saturday will mark his 60th professional MMA fight, on top of a professional kickboxing career. And in all that time, he says he's never felt flat in terms of passion on fight night.
"I'm an aggressive bastard in the end," Overeem said. "If you're a fighter, you need to have that. This is a sport, it's regulated, but I am also thinking about what I'm going to do to the other guy. And what I'm going to do to him is I'm going to hurt him.
"I don't want to kill him. I don't want to hurt him permanently. But I want to attain the most beautiful knockout or submission possible. And for that, you have to be a little mean, have a little ego, and you have to be a little selfish."
And for Ngannou, motivation is the easiest part of fighting professionally. The 31-year-old rose from a life of poverty in his native Cameroon and France.
"My strength and power is all about my mind," Ngannou said. "When I look back on where I'm from, my family, it's kind of scary. I don't want my kids, my son, to live the same thing I lived. I hope that I can give to my mom and she will be proud of me. She gave all she had for us. That is my motivation."
Fight breakdown
The question here is: Do you need to see it before you believe it with Francis Ngannou?
Because we haven't seen it yet. Not against a championship-caliber opponent. We've seen an insanely athletic, relatively inexperienced heavyweight prospect ace every test he's been faced with. But this matchup is uncharted territory.
Could Ngannou be the best heavyweight in the world? It's possible. He looks like a phenom.
But could this also be way too much -- way too soon -- for a man who only started training four years ago? Absolutely it could.
That mystery is one of the most intriguing things about Ngannou. He was very raw when he came into the UFC two years ago. And his three most recent fights have all ended inside two minutes, which means he didn't show a whole lot.
How well-rounded is he? How does he hold up in later rounds? How does he react to getting hit? What flaw in his game haven't we seen yet? What strength haven't we seen? No idea.
Physically, he's a gift to a historically malnourished division. It's rare to see a fighter enjoy advantages both in size and speed. Usually, one is forfeited for the other. Not with Ngannou. He's a towering 6-foot-4, 250-pound athlete, who is lightning quick for a heavyweight.
In his prime, the same was said about Overeem. At 37, he's still steamrolling most opponents, but he is slowing down. Since dropping three of four in 2014, he's taken a very measured, calculated approach to his output. He's conserving energy, and even then, still slowing down in later rounds.
Overeem will test Ngannou's patience. Any boos from Detroit will have zero effect on the veteran. If that happens, might Ngannou, in the biggest fight of his career, start to press and leave an opening for Overeem's clever counterstriking? That will be something to watch.
Prediction: Ngannou via TKO, second round.