GGG is fighting a guy within 8-13 in the rankings when he has 11 defenses as a champion. It seems like a mismatch. Khythrov is a good deal better in terms of style and pedigree than Lemieux and Lemieux fought Rubio, but lost. Rubio is a gatekeeper the WBC has kept around because he is Mexican.
Rubio is a kinda so-so opponent for Golovkin, but would be a massive step-up for Khytrov... now, would Yevgen be up to that challenge? We saw how a considerably more polished Amateur star Lomachenko was foiled by a wily veteran pro in Salido, and Rubio is of a similar mould. What I've seen of Khytrov so far leaves me thinking he's still leaving too many openings that could be exploited by a solid opponent. In an ideal world where a coupla losses didn't consign fighters to the scrap heap, Rubio - Khytrov would make a very good step-up for the Ukrainian, but right now I think he still needs to gain a little more experience in the pro ranks.
He should be up to Bursak, Uzcategui, Adama, or Macklin, Rubio is a little too tough a task this early he's only had 6 fights, calm down.
Why would Rubio fight Khytrov when he was Cotto's mandatory and now he's fighting the best guy in the division?