A Nanaimo area product, MacKay graduated from Oak Bay High School.
He missed eleven games of the 1978 North American Soccer League season as the Nanaimo school board would not approve a leave of absence from his teaching position.
[2] MacKay played nine times, scoring one goal, for the Canadian national soccer team.
He played in four 1974 FIFA World Cup qualification matches in 1972, scoring a goal against the Americans in a 2–2 draw.
Canada lost the match played in Edmonton 1–2 to Cuba and failed to advance.