As director he had control of first-team affairs, but like Frank Watt could not pick the team under the Director's Committee. However he had more influence on who could play than Watt had during his time at the club, and in fact did not believe that one man should have sole responsibility for picking the team. He was manager of the club with the Directors Committee from 1938 to 1954, aside from a period from 1947 to 1950 when George Martin took over the role. In 1943, Seymour gave a trial to a 19-year-old Jackie Milburn, who later became a club legend himself. The club won the FA Cup in 1951 and retained it in 1952 whilst Seymour was at the helm. Seymour became the first person in English football history to win the FA Cup with the same club as a player and manager.