Born in England, he made two appearances for the Wales U17 national team.
Walker was the latest in the production line of young goalkeepers at Sixfields following Mark Bunn and Chris Dunn.
Walker, along with Alex Konstantinou and Michael Jacobs, were awarded professional contracts for the 2010-11 season.
[1] He made his Football League debut on 25 April 2011 as a second-half substitute for Steve Collis in a match against Stockport County.
[2] On 31 January 2011 Walker and teammate Ashley Corker were released by mutual consent from the Cobblers.