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.
"I could of done all that stuff but once someone stepped on my foot, I would of tapped out. My feet are my weak spot! You step on my feet, I'm gonna tap out!"
FYI, if you're not familiar with MMA rules ... stomping on your opponent's feet IS allowed.
Tyson -- who has recently worked with fighters like Francis Ngannou and Rashad Evans -- started boxing at an early age ... and became the youngest heavyweight champion of all-time at 20 years, 4 months when he beat Trevor Berbick in 1986.
UFC 1 didn't take place until late-1993 ... while Tyson was in prison.
Still, ya gotta wonder how Tyson -- with his insane natural ability and work ethic -- would've fared if he chose the Octagon over the squared-circle.