Francis Ngannou and Ciryl Gane are set to collide on January 22 in California at UFC 270.
The pair used to be training partners so will know each other very well and could be set for a good fight in the New Year.
Ngannou's most recent fight was back in March at the UFC 260 event. The 35-year-old secured a second-round knockout victory over Stipe Miocic. The Cameroonian was crowned the heavyweight world champion in the process.
However, 'The Predator' became inactive and therefore UFC president created an interim heavyweight title. The new title was won by Gane at UFC 265 back in August.
Francis expressed he was not happy with the UFC's decision to create the interim belt, but is positive he can defend his original heavyweight title against his former training partner.
For his upcoming fight, Francis spoke to Mike Bohn at MMAJunkie, where he posed for a photo showing his decrease in muscle mass.
We are used to seeing Ngannou looking heavily jacked, but in this new photo, he certainly looks a lot less stacked, with fans even saying he looks 'depleted'.
Below you can see a side-by-side comparison and it's easy to see that the heavyweight has certainly lost a lot of muscle mass.
Read more: UFC 270: Date, Fight Card, Tickets, Location, Rumors, UK Start Time And Everything You Need To Know
Gane has a theory on why Ngannou has lost so much muscle mass and said recently that he knows the Cameroonian can 'handle his power' and this is why he has had a change in physique.
“I think Francis Ngannou did a lot these last years, and he probably improved and he’s more intelligent. And that’s really great. He’s really well rounded now, and I think it’s going to be more like that. Because he knows I can manage the power. I think he knows I can manage the power. So maybe he should be a smart fighter this day [when we fight].”
Gane went on to say: “I’m going to manage the fight. I’m going to win after five rounds.
"Maybe before (I win) with a submission or something like that, why not? Why not?”