He holds an Irish passport and was therefore not considered an overseas player when playing for Worcestershire County Cricket Club.
Mason started his career with Western Australia in 1996–97, and made his senior debut in a February List A win over Tasmania, taking the wicket of Michael di Venuto.
Six days later he made his first appearance in first-class cricket in a drawn Sheffield Shield match against Queensland, but could manage only 1-72.
Mason's first-team experience at Worcester began in the Benson & Hedges Cup, where he took seven wickets in three matches.
He struggled with injuries through 2007 and 2008 before returning to the side and in August 2008, signed a deal with the club which saw him assume the dual role of player and bowling coach in 2009.