Rubuta ci gaba don wannan sakin layi - Matashi Cotto ya halarci gasa da yawa na duniya, waɗannan sun haɗa da: Gasar Zakarun Duniya ta Junior ta 1998 da aka yi a Buenos Aires, inda ya gama a matsayi na biyu yayin gasa a rukunin nauyi. Nasara uku da ya samu a nan ta maki ne, sakamakon sune: Andrey Kolevin na Ukraine ta maki 15<unk>3, Dana Laframboise na Kanada ta maki 6<unk>1, da Darius Jasevicius mai wakiltar Lithuania 9<unk>5. Rashin nasararsa kawai ya kasance ga Anton Solopov na Rasha ta maki tare da ci 8<unk>9. A cikin 1999, Cotto ya yi gasa a Wasannin Pan American da aka yi a Winnipeg, Manitoba, Kanada. Ya yi yaƙi sau ɗaya kawai a cikin asara ga Dana Laframboise na Kanada ta maki tare da ƙimar ƙarshe na 2<unk>5. Bayan halartarsa a gasar Pan American, Cotto ya kasance wani ɓangare na gasar zakarun duniya
a birnin Houston, Texas. Ya yi rashin nasara a fafatawarsa da Robertas Nomeikas. A wasansa na karshe na 'yan wasa, Cotto ya wakilci Puerto Rico a matsayin mai nauyin Welterweight a Wasannin Olympics na Sydney na 2000 inda ya yi rashin nasara ga Mahamadkadir Abdullayev na Uzbekistan ta maki. Cotto ya yanke shawarar zama kwararre bayan rashin nasara ga Abdulaev, ya ƙare aikinsa na mai son tare da rikodin 125<unk>23.