He played junior hockey for the Toronto Marlboros, Toronto Native Sons, and the West Toronto Nationals. Heron won the Memorial Cup in 1936 with West Toronto. Heron played for the senior Toronto Goodyears in 1936-37 and 1937-38, leading the Ontario Hockey Association Senior League in scoring in 1937-38. He turned pro in 1938-39 with the Syracuse Stars. He was a regular for the Toronto Maple Leafs in 1939-40 and 1940-41, and then was loaned to the Brooklyn Americans in 1941-42. The Americans then loaned him to the Montreal Canadiens in mid-season.