Selected in the 2000 rookie draft, he was elevated from the Kangaroos' rookie list in 2001, where he made his debut as a 20-year-old.
A crumbing forward, Harding had the tendency to miss simple shots at goal on the run, although he had a high work rate. He topped the Kangaroos goalkicking in 2003 with just 33 goals, an equal personal best season haul.
In 2005, Harding moved from being a fringe player to more of a regular role. This improved in 2006 when he played 19 games out of 21 until the final training session before Round 22, the final week of the season. Bad luck struck when he suffered a serious knee injury, requiring a knee reconstruction, keeping him out of playing for around 12 months.
