FitzSimons has been a sports columnist for The Sydney Morning Herald since 1987 and has written for it since 1988. He has also written columns for The Age, The Canberra Times, and The Brisbane Courier-Mail. He won the Walkley Award in 1992 for his work on a story called "The Making of an Idiot". The story focused on Australian cricket captain Ian Chappell who had been banned from playing cricket for three years by the England Cricket Board over his role in the 1981 Indian tour scandal. It was later revealed that part of the reason for the ban was because Chappell had refused to go to India to play a series of matches against English county teams despite being offered money to do so. Since then, he has written several other columns about different sporting issues such as doping in sport, match fixing, and corruption. His book A Cocky Season: One man's fight with drugs and death wishes to change baseball forever was published in 2001. The book focused on former Major League Baseball player Gary Thorne who had been involved in one of the biggest drug scandals in baseball history - he had attempted to kill himself while serving a sentence for attempting to smuggle heroin into prison.