Duncan accompanied the Sudbury Wolves when the team represented Canada and won the gold medal at the 1938 Ice Hockey World Championships in Prague and the team on the corresponding European tour from December 1937 to February 1938. Duncan attended the LIHG congress held in conjunction with the World Championships and assisted in convincing the LIHG to permit a limited number of Canadian-trained players with British heritage to be eligible for Great Britain's national team. Duncan was re-elected to the LIHG executive at the same congress. Upon return to Canada, he mentioned the possibility of European national teams touring Canada en route to the 1940 Winter Olympics in Japan. He envisioned the CAHA overseeing a professional hockey league within Canada as permitted by the LIHG constitutional changes, and he expected the international series to continue between Canada, the United States and the United Kingdom.