That would be a tough chalenge to GGG. Rubio is solid. He lost to Chavez, but has a granit chin, and has a big ko percentile. If he could land to GGG, with 59 wins and 51 by KO, he could test GGG's chin. Rubio is underrated and should have a shot at GGG.
I mentioned it on 2 threads before that, I agree it would show how good GGG's punching power truly is, and how good his chin is, if he could stop Rubio that would be quite an accomplishment. It would also be a good measuring stick to see how well he'd do at SMW, Rubio is very big for a MW and not a blown up JMW.
