UFC star Islam Makhachev needed an opponent after Beneil Dariush suffered a freak injury while training ... enter MMA vet Bobby Green, who took the fight on JUST 10 days' notice.
Why take a fight against a guy who hasn't lost in 6.5 years?! TMZ Sports asked Green.
"I know, I know. It's f**king crazy. Put the weight on, take the weight off, just fought, come back and fight again. I'm f**king nuts brother, this is what I do. I try to show everybody that this is real s**t.