Career
In 1999, Walker joined the Ajax Youth Academy coming from Guarani, he was crowned World Champions with the at the 1999 Fédération internationale de football association U-17 World Championship. In July of 2000, Walker Américo Frônio signed with Ajax. He also made a great impression when he helped the reserves team to a semi-final appearance in the KNVB Cup in 2002.
During the 2002-2003 season, Walker played on loan of the Belgian satellite club Germinal Beerschot in Antwerp making a total of 21 appearances while scoring one goal.
On 6 January his contract was terminated and he returned to Brazil where he played for Atlético Mineiro. He then continued his career playing for Juventude, Náutico, Itumbiara, Rio Claro, Santo André, Sertãozinho and Botafogo SP. Club Jong Ajax International.