Following Cagna's departure arrived 1991 Copa Libertadores champion Luis Pérez as caretaker, who remained Castillo in the goal. However, despite Pérez's trust in the keeper, he again completed a poor performance and conceded five goals in the Copa Libertadores debut that Colo-Colo lost 5–2 with Cerro Porteño. On 20 February the crisis deepened with Castillo yet on goal after a 2–0 away loss with Unión San Felipe for the local tournament. Finally Colo-Colo won 3–0 to Palestino during Pérez's last caretaking match where Castillo had casual crash with Arab team striker Nicolás Canales which the Uruguayan publicly apologized him in front of the press and then via Twitter. Shortly after Colo-Colo appointed Américo Gallego as club's new coach.