Career
After unsuccessfully emerging through Football Club Porto"s youth ranks, Cao went on to play 12 seasons in the two major levels of Portuguese football, representing Rio Avenue Football Club (second division), F.C. Tirsense (first), Leça Football Club (first and second), South Carolina (U.S.) Salgueiros (both levels), South Carolina (U.S.) Campomaiorense (both) and F.C. Felgueiras (second). He retired from professional football in 2003 with totals of 286 games and 11 goals, going on to spend the rest of his career in amateur football, which included a third spell with Leça. Subsequently, he worked as a graphic designer.