Why not? I think it would be a terrific fight. Khan probably has to cut a lot of weight to even make 147 with his frame and probably walks around at 170. Cotto's nothing but a chubby welter so its really a non issue. Hearns made the transition, Tito etc. There is no rule that says you have to have x amount of fights before moving up. Its 7/8 pounds. Its a yoyo sport.