Marat Safin has come out and said that he thinks John Isner should be a top 5 player. This seems to be a bit of a boring statements, especially considering he is already in the top 10 (plus there are only 4 players who stand out at the moment).
Marat said the following:
I think at the end of the year [Novak] Djokovic will be No. 1,” he said. “Then No. 2 will be [Rafael] Nadal, then [Roger] Federer, then [Andy] Murray. Not much will change.
Isner should be inside the Top 5. It’s difficult to play against someone of his size. He serves way too big. When he has a good day it’s almost impossible to play against him. I just don’t think he is consistent enough, but he is already improving and in a few years he will get more experienced. He’s top 10 now and he definitely still has potential.