Born in Praia, Cape Verde one year before the nation gained independence from Portugal, Dos Santos migrated to France at a very young age, and started his professional career at AS Monaco FC. He then played for Montpellier HSC and Olympique de Marseille, spending four Ligue 1 seasons with the latter: with "L'OM", he appeared in nine complete matches in the 2003–04 UEFA Cup, including the 0–2 final loss against Valencia CF which would be his last match for the club.