Muscat was dubbed the "most hated man in football" by then Birmingham City player Martin Grainger in 2000 after a reckless tackle against international teammate, Stan Lazaridis. He seriously injured both Craig Bellamy and Christophe Dugarry, the latter in a friendly international between Australia and France in 2001 with a sliding tackle from behind. The French manager Roger Lemerre dubbed the tackle "an act of brutality". It was speculated that Muscat's temperament was the reason he was never selected for inclusion in an Old Firm derby during his time at Rangers.