Rios: Pacquiao's chin is his weakness

By Chris Williams: Former WBA lightweight champion Brandon Rios (31-1-1, 23 KO's) is convinced that the weakness for Filipino Manny Pacquiao (54-5-2, 38 KO's) is his chin after Manny was brutally knocked out last December by Juan Manuel Marquez in Las Vegas, Nevada. Pacquiao is not going to be fighting in the U.S for his