Career
After being signed by the former Brisbane Roar !Brisbane Roar coach Frank Farina on a two-year contract, Zullo played five of the six opening games of the season, coming on as a substitute. He previously played in the Brisbane Premier League for the Brisbane Strikers During a match against Sydney Football Club, Zullo limped off the field with a torn thigh muscle which ruled him out for 6 weeks. At the end of the 2008-2009 season, Zullo received offers from Dutch Eredivisie clubs Football Club Groningen and Nippon Electric Corporation Nijmegen but declined both offers and cited his preference to stay in the A-League for another season.
On 2 April 2010, along with fellow Roar players, Thomas Oar and Adam Sarota, Zullo joined Dutch side Utrecht on a three-year deal, in a collective transfer deal rumoured to be worth in excess of A$1.8 million.
He made his debut for Utrecht in a 1-1 draw with Nippon Electric Corporation Nijmegen on 28 February 2011, coming off the bench on the 81st minute. On 29 August 2013, he signed a one-year loan deal with Australian A-League club Adelaide United.
On 14 July 2015, Zullo signed a one-year deal with Melbourne City. He was also a train-on player with the national U-17 squad, the Joeys, at 2005 Fédération internationale de football association U-17 World Championship in Peru.
On 28 January 2009, Zullo made his full international debut, coming on as a substitute in a 0-0 draw with Indonesia in the group stage of qualifying for the 2011 AFC Asian Cup.