High-flying Aussie soccer coach Ange Postecoglou is flying high in Europe and a man that played under him a decade ago, Daniel Mullen, lifts the lid on what makes Postecoglou so successful. The former Socceroo talks about how big the upcoming December 2022 Old Firm Derby, to be played outside of Scotland for the first ever time in Sydney, will be for the sport and whether he'll get over there for it. The current Campbelltown player, who also won the Asian Champions League in 2014, also discusses his career.