Trailer impressed Tottenham Hotspur while playing for Wales schoolboys in 1932 and was invited to join the club's junior side. He later earned an amateur contract. At the age of 16 he signed professional forms with the club's "nursery" teamNorthfleet United. In October 1938 Trailor was offered a professional contract with the Spurs. During World War II he served with the Royal Artillery. He was wounded during the retreat from Dunkirk and returned to service after recovery. On several occasions he turned out for Tottenham in war–time matches. The wing half returned to the club in 1946 and went on to feature in 12senior matches in all competitions. He also featured in 118 games and scored 24 goals at various levels at White Hart Lane. In August 1948Leyton Orient paid £600 for his services where he notched up a further 39 appearances. After leaving Brisbane Road he joined Bedford Town where an ankle injury ended his competitive career after making 46 appearances and scoring two goals between 1950 and 1951.
Post–playing career
After his football career had ended Trailer returned to his home town of Merthyr Tydfil where he was employed at the town's Hoover plant. Trailer died in Merthyr on 28 August 1986.