Just like there is no way that Mayweather would beat McGregor in a MMA fight, Mayweather would embarrass McGregor in a boxing match.
TMZ has some footage of McGregor sparring at the Box ‘N Burn gym in Cali and to be kind it is less than impressive.
Striking is a big part of MMA, but it isn’t the same as boxing, but McGregor & Mayweather are doing their best to keep the possibility of a fight out there.