HamAndEgger
All Star
Golovkin is too big and too powerful. All the rumors I have heard is that if Floyd ever even considered fighting a Middleweight it would be Sergio. As of right now, even if you believe Kid Chocolate or GGG would beat him, Sergio is still the lineal champ. He is a big name that would create a PPV that could make a lot of money. And Sergio is a smaller sized Middleweight. Not necessarily height wise, but the amount of weight he normally weighs.
Here's some more irony...
Say Cotto beats Martinez for the Middleweight title in June...and being Cotto has no restrictions...how funny would it be for Floyd to challenge Cotto for the (would be I assume) Lineal Middleweight title