Mike Tyson says if he would've gone into mixed martial arts -- instead of boxing as a teenager -- he would've been a helluva MMA fighter ... as long as no one stepped on his feet!!
Yes, one of the most ferocious men the world has ever seen has a weakness ... and it's having his feet stomped.
TMZ Sports talked to 54-year-old "Iron Mike" -- a huge UFC fan -- about how he would've fared if he dedicated his life to a different combat sport.
"I could of done all that stuff," Tyson says.