Juan Manuel Marquez (R) of Mexico is hit by Juan Diaz of the US before defeating him during their WBA-WBO lightweight World championship bout at the Mandalay Bay Resort in Las Vegas on July 31, 2010. Mexican veteran Juan Manuel Marquez was defending his lightweight title against American Juan Diaz in a rematch of their title slugfest from last year that brought Marquez two titles. MARK RALSTON / AFP/Getty Images

WBA/WBO lightweight champion Juan Manuel Marquez (L) hits Juan Diaz in the 11th round of their bout at the Mandalay Bay Events Center July 31, 2010 in Las Vegas, Nevada. Marqez retained his WBA and WBO lightweight championship belts with a unanimous-decision victory over Diaz. Ethan Miller / Getty Images

Juan Diaz (R) throws a right at WBA/WBO lightweight champion Juan Manuel Marquez in the third round of their bout at the Mandalay Bay Events Center July 31, 2010 in Las Vegas, Nevada. Marqez retained his WBA and WBO lightweight championship belts with a unanimous-decision victory over Diaz. Ethan Miller / Getty Images

Mike Tyson holds his daughter Milan as he arrives at the Juan Manuel Marquez and Juan Diaz bout at the Mandalay Bay Events Center July 31, 2010 in Las Vegas, Nevada. Ethan Miller / Getty Images

WBA/WBO lightweight champion Juan Manuel Marquez (R) hits Juan Diaz in the ninth round of their bout at the Mandalay Bay Events Center July 31, 2010 in Las Vegas, Nevada. Marqez retained his WBA and WBO lightweight championship belts with a unanimous-decision victory over Diaz. Ethan Miller / Getty Images

Juan Diaz is tended to in his corner during his bout against WBA/WBO lightweight champion Juan Manuel Marquez at the Mandalay Bay Events Center July 31, 2010 in Las Vegas, Nevada. Marqez retained his WBA and WBO lightweight championship belts with a unanimous-decision victory over Diaz. Ethan Miller / Getty Images

Juan Diaz (L) and WBA/WBO lightweight champion Juan Manuel Marquez battle in the 10th round of their bout at the Mandalay Bay Events Center July 31, 2010 in Las Vegas, Nevada. Marqez retained his WBA and WBO lightweight championship belts with a unanimous-decision victory over Diaz. Ethan Miller / Getty Images

WBA/WBO lightweight champion Juan Manuel Marquez (L) hits Juan Diaz in the second round of their bout at the Mandalay Bay Events Center July 31, 2010 in Las Vegas, Nevada. Marqez retained his WBA and WBO lightweight championship belts with a unanimous-decision victory over Diaz. Ethan Miller / Getty Images

Juan Diaz (L) and WBA/WBO lightweight champion Juan Manuel Marquez battle in the third round of their bout at the Mandalay Bay Events Center July 31, 2010 in Las Vegas, Nevada. Marqez retained his WBA and WBO lightweight championship belts with a unanimous-decision victory over Diaz. Ethan Miller / Getty Images

A showgirl holds up a round card before Juan Manuel Marquez of Mexico defeated Juan Diaz of the US during their WBA-WBO lightweight World championship bout at the Mandalay Bay Resort in Las Vegas on July 31, 2010. Mexican veteran Juan Manuel Marquez successfully defended his lightweight title against American Juan Diaz in a rematch of their title slugfest from last year that brought Marquez two titles. AFP PHOTO/Mark RALSTON (Photo credit should read MARK RALSTON/AFP/Getty Images) MARK RALSTON / AFP/Getty Images