 Wilcox made his highest score in May 1965 when, going in to bat against Worcestershire with Essex at 154 for 6, he added 139 for the seventh wicket with Trevor Bailey and finished with 87.Essex won by 48 runs.Nevertheless he made only four Championship appearances that season, finding himself out of the team after a second-innings duck against Somerset, and he did not appear in the County Championship again until August 1967, when he played his last four matches.