Mason is a tall fast bowler who, despite being born in Western Australia, is eligible to play for Worcestershire through an Irish passport. He turned down the chance to represent Ireland in their attempts to qualify for the 2007 World Cup.
Mason has impressed for his county, taking 50 first-class wickets in the 2003, 2004 and 2005 seasons, and has been a permanent fixture in the first XI when injuries have permitted.
His early career in Western Australia was blighted with niggling injuries but his move to Worcestershire in 2002 resulted in him taking 22 championship wickets in just six matches.
Mason signed a contract extension in August 2005 keeping him at the county until the end of the 2008 season as he impressed with 51 championship wickets in the year.
Mason missed the beginning of the 2007 domestic season after undergoing surgery on a shoulder problem during the winter, playing just one match in the whole summer and he continued to battle for fitness through the 2008 season.
In August 2008 he agreed a new playing deal for 2009 which would also see him act as bowling coach at New Road.