Sergio Martinez's manager says Mayweather fight is impossible now

By Dan Ambrose: With Floyd Mayweather Jr. now fighting on Showtime instead of HBO, Sampson Lewcowicz, the manager for WBC middleweight champion Sergio Martinez, says that a fight between Martinez and Mayweather is now out of the realm of possibilities due to the two fighters being on different networks. Lewcowicz said to ESPNDeportes.com "No chance,