Anybody who watches boxing regularly knows that Floyd has hand issues, he's been known to use cortisol to deal with the frailty in his hands after decades of boxing. Floyd knows that at his current age, Canelo would be a tall order. I'm not saying Floyd can't win, but rather, Floyd might actually lose. During his prime, Money has been stellar, but against a younger, improved, stocky guy like Canelo, the probability of Floyd injuring a hand mid-fights is a huge possibility.
This is why Floyd is having fun calling out MMA fighters since it'd be easy for him to enter the ring and win a safe decision. He wouldn't even need to spar more than once a week and simply work on cardio.