Many Americans visit Mexico each year, but it's often to places like Acapulco, Cancun and Cabo San Lucas. I've frequented only one real resort city, Mazatlan, and once you get away from the Zona Dorada you pretty much see the real Mexico, well, the one I prefer anyway. Many times, these resort cities don't represent what Mexico is all about. You have to go away from the touristy areas to experience that. I'd suggest a trip to Guanajuato or Morelia/Quiroga/Patzcuaro to get a taste of Mexico.
Soccer and resort cities also don't often mix. If you take a trip to Acapulco, for instance, and want to see a first division soccer game, you're out of luck. That's been the case for years.
Except for now, you have options. Not only does Cancun feature top-flight futbol, their team is pretty good. Champions in fact.