Cowan played centre half for Manchester City for 11 seasons, captaining the team in the early to mid-1930s. He is the only player to have represented Manchester City in three FA Cup finals, as a runner-up in 1926 and 1933, and as a winner in 1934. Internationally, he gained three England caps between 1926 and 1931. In total he played 407 times for Manchester City, putting him 12th in terms of all-time appearances. In 1935, he transferred to Bradford City, and subsequently moved to Mossley as player-manager.