After being spotted playing Australian rules football in a services team in Darwin by Ray Stehr in 1941, Cooper joined the Eastern Suburbs club.
In 1946 Cooper represented Sydney, New South Wales and Australia; he played in all three tests against the Great Britain Lions that year at home.
[citation needed] The Gregory's reference describes him as a bullocking, bruising winger who was a great finisher of back-line movements.
Cooper played left-wing in Huddersfield's 4–11 defeat by Bradford Northern in the 1949 Yorkshire Cup Final during the 1949–50 season at Headingley, Leeds on Saturday 29 October 1949.
[5] Cooper played on the wing and scored two tries in Huddersfield's 15–10 victory over St. Helens in the 1953 Challenge Cup Final during the 1952–53 season at Wembley Stadium, London on Saturday 25 April 1953, in front of a crowd of 89,588.