 In 1921, Gilbert made his county cricket debut with Worcestershire, and played a considerable number of games for the county in that and the following summer.Apart from one game for MCC against Oxford in 1921, and one for Free Foresters against Cambridge in 1922, all his matches during this period were for Worcestershire.He enjoyed considerable success, taking 84 first-class wickets at 24.54 and 85 first-class wickets at 28.55 in the respective years,
with a best bowling performance of 7–60 for Worcestershire against Nottinghamshire at Worcester in August 1921.