As much as Antonio Brown has been in the news for his Twitter fingers instead of his hands, the former NFL All-Pro wide receiver is still an elite athlete. Heck, he kicked a punter square in the chest in a freaking game. If that doesn't show how wild he is, nothing will.
Even though he's older, he is still quicker and stronger than Paul will ever be. Paul couldn't even beat KSI let alone a dude that has literally spent his entire adult life working out for a living.
Don't disrespect Brown's athleticism. He would kill Paul in the ring.