Walker was born in Toowoomba in Southern Queensland on 13 September 1976, and is the eldest of a trio of brothers who would all become rugby league footballers.
While attending St Mary's Christian Brothers College in Toowoomba in 1993, Walker was selected in the Australian Schoolboys team.
Walker was selected to play for the Brisbane Broncos in the 1997 Super League Grand Final from the interchange bench.
In the 2000 NRL season, Walker was limited to only 11 games for Brisbane and missed out on playing in the club's premiership victory over the Sydney Roosters at Stadium Australia.
[6] Walker spent two years at Souths and his last in the 2006 NRL season saw the club finish last on the table and claim the wooden spoon.