Born in Bromley Agana started his career in non-league football, before turning fully professional with Watford. He later moved to Sheffield United where he enjoyed the most prolific spell of his career, making over 100 appearances for the Blades and playing in the top tier of English football. He subsequently moved to Notts County for whom he also played over 100 games before finishing his career playing for a number of non-league teams. He had a brief spell as manager of Leek Town before retiring from football in 2002.