He has a sneaky right uppercut, but it was shown in the Diaz fight that another top striker will begin to time it and counter it. Because years of fighting smaller, lesser competition, he has developed bad habits and never focused on the basics of boxing.
Just look at this gif, he gets tagged as he's going to throw a lead uppercut, with his power hand (and he doesn't even attempt to mask it with a feint or a feeler jab). That is a technique that shouldn't even be considered in boxing, ESPECIALLY from a distance (But against guys like Brimage, he got away with this shit).