Fluminense FC
Born in Linhares, Espírito Santo, Isaías started his career with Fluminense FC, where he had an unassuming spell. He then represented Friburguense Atlético Clube and Associação Desportiva Cabofriense, and moved to Portugal in 1987, gradually moving up the ranks: first with Rio Ave F.C. then Boavista FC, arriving at S.L. Benfica in 1990.