Guy McGregor began his career as a rugby player, but a knee injury in his teen years led him to take up field hockey instead. He soon became a star at Gisborne High School and captained the team in 1948. After graduation, he entered Otago University for a degree in physical education, but continued to play hockey as an amateur. He joined the national squad in 1952 and represented New Zealand at two editions of the Olympics, finishing sixth and fifth in 1956 and 1960 respectively. By career, he taught physical education at several institutions, before settling into Auckland Teachers’ College. Earlier in his career, he also played cricket.