He played junior hockey for the St. Michael's Majors from 1960 to 1962, winning the Memorial Cup in 1961. In 1962-63 he played for the University of British Columbia. In 1963-63 Mackenzie joined the newly-formed Canadian National Team and stayed with the team through 1967-68. He represented Canada at the 1964 and 1968 Olympics and the 1965, 1966, and 1967 World Championships. In 1969-70 he was the player-coach of the Seibu team in Tokyo, Japan. He retired in 1970. In 1972-73 he was the coach of the junior Sudbury Wolves for part of the season.