A product of Highland League club Elgin City, Walker signed for Leicester City aged 17. He didn't settle in the Midlands though, and returned to Scotland within the year, signing for Motherwell in 1981. Two years later he signed for Rangers, where he soon established himself as their first choice goalkeeper. The arrival of Chris Woods as part of the Souness revolution meant that Walker lost his place. Walker did play in the 1987 Scottish League Cup Final against Aberdeen, which Rangers won after a penalty shoot-out.