Career
Zainuddin played as a striker for the Bruneian representative team in the Malaysia league in the late 80s and 90s. He made several appearances for the national side, and scored a goal in a 1986 World Cup qualifier against Hong Kong. Zainuddin became a football coach afterwards, taking charge of the national team for 6 games at the 2002 World Cup qualifying.
He then turned to club football in 2008 with Department of Administration and Management Gunners, coaching them until 2011 when the season was aborted abruptly.
He was appointed Brunei Under-19 head coach in 2011. His last known position was the Brunei Under-23 assistant coach in 2013.
