 Vlašić akatanga kare mumakwikwi epasi rose: akakwikwidza mumakwikwi eWorld Youth Championships, achipedza wechisere, uye akamiririra nyika yake kekutanga kumaOlympics eSydney muna 2000. Kunyange zvazvo mitambo yeOlympics yakaratidza kuti akanga asina kugadzirira kukwikwidza pamwero mukuru, akazviratidza kuti akanga ane unyanzvi zvikuru pamwero wechiduku nokukunda 2000 World Junior Championshipsnokusvetuka kwemamita 1,91. Akanga ari mukwikwidzi wenguva dzose pamisangano yevatambi vepamusoro uye aigara achivandudza, achikodzera zvimwe zviitiko zvepamusoro zvevakuru. Vlašić akapedza ari wechitanhatu pa2001 World Championships muEdmonton aine chiratidzo che1.94 m, mhedzisiro yakatungamira IAAFs Ed Gordon kumucherechedza senyeredzi yeramangwana muchiitiko ichi. Akapedzisa gore racho nekukunda menduru yake yekutanga yegoridhe pamutambo wepasi rose, achitora nzvimbo yekutanga mu2001 Mediterranean Games. 