Harper began his professional playing career with
Sydney City in 1986, their last season in the
National Soccer League. Harper spent the
1987 National Soccer League season playing for
Sydney Olympic. In January 1989, Harper signed for
St George after spending much of 1988 travelling in Europe. After several years with St George, Harper was sold to
Marconi-Fairfield for an $18,000 transfer fee. In the 1993 NSL grand final, Harper scored from a penalty kick to give Marconi a 1–0 win over
Adelaide City. In 1997, Harper signed a two-year deal with the
Brisbane Strikers. He cited a desire to continue commentating for the
Special Broadcasting Service (SBS) as a motivation for staying in Australia, despite overseas interest. Harper joined the
Newcastle Breakers at the start of the 1999–2000 NSL season. With the Breakers on the brink of collapse, Harper and a number of other players walked out in September 2000, citing breaches of contract by the club. Harper joined the new
Newcastle United along with a number of fellow former Breakers. Last playing in 2001, Harper made 321 appearances, scoring 100 goals. ==Writing==