Hard.
TMZ Sports ran into the 38-year-old (retired, for now, at least) former UFC champion at LAX on Friday ... and asked him about the Problem Child's foray into MMA.
"Stop trying to fight little dudes. F***ing [155] pounders. You're a middleweight. If you want to fight a middleweight, I got hands. We can do anything we want. I really don't care. I'd beat that guy in my sleep."
As we previously reported, 26-year-old Paul recently signed a multi-fight, multi-year deal with PFL ... and wasted no time by calling out Nate Diaz for a boxing and MMA fight.