The real fight should be McGregor vs Pacquiao. Pacquiao chased Mayweather all over the ring during that fight in Las Vegas. The boxing authority let Mayweather have an IV before the fight but not Pacquiao. Read about it on Wikipedia. McGregor thinks differently than a boxer. If Mayweather locks McGregor up in the middle of the ring, McGregor may just return the foul with a viscous head butt (another foul) or a hard knee to the ribs. Either of these "return" fouls would be a rude awakening to a trained boxer.