pˈɛɹɛz wʌz kənsˈɪdɚd təbi wˈʌn ʌvðə bˈɛst ɡˈoʊlkiːpɚz ɪn mˈɛksɪkˌoʊ ænd tˈʊk ˌoʊvɚ ðə spˈɑːt fɔːɹ stˈɑːɹɾɪŋ ɡˈoʊli dˈʊɹɹɪŋ ðə tˈuː θˈaʊzənd tˈuː wˈɜːld kˈʌp kwˈɔlɪfˌaɪɚz, ɡˌoʊɪŋ ˌɔn tə plˈeɪ ɪnðə tˈuː θˈaʊzənd tˈuː wˈɜːld kˈʌp æz ðə fˈɜːsttʃˈɔɪs ɡˈoʊlkiːpɚ.
Pérez was considered to be one of the best goalkeepers in Mexico and took over the spot for starting goalie during the 2002 World Cup Qualifiers, going on to play in the 2002 World Cup as the first-choice goalkeeper.