Adelaide United Football Club CEO Sam Ciccarello said that after a very successful career with the club that Michael had today handed in his resignation to pursue other opportunities.

"We all owe Michael a great deal of gratitude for his leadership in the club and especially of the football department through its first four years of its existence and in helping to shape the club into being one of the most successful and competitive Hyundai A-League Clubs," he said

"Michael has been a key advisor and mentor to our football staff especially to Head Coach Aurelio Vidmar and Assistant Coach Phil Stubbins and he has left a great legacy to Adelaide United."

Michael Petrillo said that after being with the club for four years it was time for him to look for new challenges.

"I feel the time is perfect for me to leave now on a high after our performances during the last 12 months through the AFC Champion's League campaign and of course in the domestic competition," he added.

"It's the right time now for me to move on with the football department in great shape, and it's also good timing for the club to appoint a new director of football in the off season. I look forward to having a break and moving on to the next stage of my career."

Adelaide United will make an announcement regarding Michael Petrillo's replacement in the near future.