Career
He started his career at the Natal Sharks, representing them in the Vodacom Cup in 1999 and 2001. He then the joined Mighty Elephants in 2002, where he played for four seasons before moving to the Free State Cheetahs in 2006. He announced his retirement at the end of 2011.
After two seasons as head coach at Grey High School, Duncan joined the Free State Cheetahs in November 2013 to become the coach of their Vodacom Cup and Under-21 sides.