The 23-year-old batsman's decision came as a result of the the ever-rising mismanagement and corruption in the Zimbabwe cricket board.
''I had dreamed of playing for Zimbabwe all my life, but, over the years, it has changed a lot. The young guys have been left to clean up the mess. In the last three years, I don't feel like my game has improved, and I believe that will happen in Australia,'' the 23-year-old Sibanda told Sydney Morning Herald.
''I know that, in the long run, I can better my career here. I wouldn't mind playing for A-grade or Shires team, so long as I felt my game was improving,'' added the tennage batsman, who has represented his country in the ongoing Caribbean World Cup.
Earlier, former captain Tatendu Taibu also opted for premature retirement because of crisis. He shifted his base to South Africa, playing for a provincial side, following the footsteps of Heath Streak, Andy Flower, Henry Olonga and Mark Vermeulen.