Despite some impressive performances, especially in the 1999–2000 season, during which he was a member of Chelsea's FA Cup winning squad, albeit as an unused substitute in the final, he was unable to establish himself in the London side.
He ultimately made 42 appearances for Chelsea and scored two goals, both of which were winners in the 1999–2000 FA Premier League against future club Watford[3] and Leeds United.
[8] Harley was equally unable to establish himself in the Fulham side, despite a somewhat outstanding goal against Aston Villa, in which he beat Peter Enckelman with a 40-yard strike.
Despite his ability his form dipped mid-season, but later recovered to end the campaign with a number of solid performances, culminating in his winning the "Player of the Season" award.
At the start of the 2007–08 season, Harley found himself playing in the unaccustomed position of left-sided midfielder or on the bench, replaced by new signing Stephen Jordan.
[13] On 14 July 2010, Harley signed for the Football League Two Champions Notts County on a two-year deal[14] and established himself as a regular member of the team in the 2010–11 season.
In September 2011 he turned out for Australian A-League side Melbourne Victory in a bid to win a full-time contract,[15] the move, however, fell through.