On 1 May 2008 Mullen was appointed as Adelaide United"s inaugural youth team coach. In 2013, Mullen was appointed the new manager of National Premier Leagues South Australia football club Campbelltown City South Carolina. In addition to being a manager, Mullen is also a coach instructor, instructing coaches in the AFC C license for FFSA. Player Manager.
With Adelaide City: Nationaal Samenwerkingsprogramma Luchtkwaliteit Championship: 1986, 1991–1992, 1993–1994 Nationaal Samenwerkingsprogramma Luchtkwaliteit Cup: 1989, 1991–1992 Personal: FFSA Award of Distinction: 2005 With Green Gully: VPL Championship: 2003-2004 With Bulleen Zebras: Victorian Italia Cup: 2002 U-14 Victorian Super League: 2003 U-14 Victorian Super League Cup: 2003.
