After his first two seasons with the Leafs, he played for the Atlanta Flames for a year before playing with the New York Islanders for the rest of his NHL career.
After retiring from playing, MacMillan became a coach which saw him coach the Colorado Rockies up until they relocated to become the New Jersey Devils and he was their coach for the first two seasons of their existence. He also served as the GM of the Rockies in their final season in Colorado.
MacMillan was known most for his determination and humbleness as a person.
Our thoughts our with his family during this difficult time.