It's hard to think of a boxer these days who could transcend his sport, interact with a star from another sport. Try explaining it to the kids of today, and they'd look at you like you had two heads - before they went back to their phones.
But that's the greatness of Ali. He was a talker, and proud of it. So when he heard about Brian Clough, and all of the quotable lines that the famous manager had - he called him out:
Knowing everything you've heard of Clough, was that the reaction you were expecting.