Thats who I'd pick if I were managing JMM. Its not only the better money fight for Marquez, but Juan Diaz style lends itself to a great fight and matchup.....and legacy wise, it heightens JMM's career resume as top notch. In his mid-thirties, a fight against a slickster like Joan Guzman would imo be a harder task for JMM. So its a no brainer as far as I'm concerned. The Juan Diaz fight for JMM is a better matchup stylewise for him, and he gets more money and notoriety fighting Diaz!