 On 14 October 1961, Irvine made his debut for the Burnley reserve side, scoring a hat-trick in the 6–1 victory over Barnsley.Both the A team and the reserves were crowned champions of their respective divisions at the end of the season, and Potts singled out Irvine for particular praise, stating that Burnley had not "had a more consistent goal getter than Willie for a very long time.