He was appointed club captain in 1955 and led Perth to the premiership that year,[2] their first since 1907.
From 1956 to 1960 he remained captain of Perth but they didn't experience anymore premiership success.
The midfielder took the field regularly for Western Australia in interstate matches and made a total of 18 appearances.
His best performances came in 1954 when he won a Simpson Medal for his effort against Victoria at Subiaco[3] and in 1956 where he was awarded All-Australian selection at the Perth Carnival.
Later, in 2004, Harper was inducted into the West Australian Football Hall of Fame as one of the inaugural inductees.