If you thought there wasn't a man alive crazy enough to call out former 2-time UFC heavyweight champ Cain Velasquez, you're wrong ... 'cause TMZ Sports found the MMA badass willing to do it.
We got Francis Ngannou -- the #6 ranked heavyweight in the UFC -- out in NYC, and we asked the 6'4" 260 pounder who he wanted to fight next time he steps in the Octagon ... his answer was simple.
"My next opponent I want is Cain Velasquez."
Cain's last fight was this past summer when he beat down Travis Browne (like everyone does) and Francis TKOd Andrei Arlovski back in January for his 9th straight win.
Time to put this collision on course.