He was a member of the team that reached the 2003 UEFA Cup Final against F.C. Porto, playing well in the games leading up the final, but considered culpable by many fans for at least one of Porto's goals in Seville. Douglas' form was generally good at Celtic, but he had the misfortune of conceding 'soft' goals in high-profile games, notably in the 3–3 draw against Rangers in October 2002 where he was badly at fault for Rangers first goal and considered to be at fault for their third also.