On leaving school in 1940, Rowley went to work for a sheet metal firm doing war work before joining his older brother Jack in Manchester. Thus Rowley began his career at Manchester United, signing as an Amateur just four days after his 15th birthday. The following day, 26 April 1941, at 15 years and 5 days old, he became the youngest ever player to feature in the Manchester United first team when he lined up alongside Jack in a war-time league match against Liverpool at Anfield.