Club career
Castillo's professional career began with América de Cali in 1994. In 1995, Castillo was loaned to second-division club Atletico Bucaramanga, and scored 8 goals in 25 appearances, helping his club win the 1995 Categoría Primera B title. He returned to America for the 1996 season having gained more experience and won his first title as a professional, the 1996-97 league championship, and finished