Club Sport Emelec
Born in Esmeraldas, Estupiñán began playing football for Club Social y Deportivo Macará and made his Ecuadorian Serie A debut at age 17. He would also play for Club Deportivo El Nacional and Club Sport Emelec in Ecuador's top division. He played several seasons in the Primera División de México with Deportivo Toluca F.C., Club América, Atlético Campesinos and Puebla F.C., winning the league with Toluca in 1974–75 and with Puebla in 1982–83.