[5] In 1934, Portsmouth finished as runner-up in the FA Cup against Manchester City, with Allen picking up and injury during the game, and a runners-up medal.
[1][6] Allen made his international debut for England at the age of 23 in a 3–0 win over Northern Ireland at Windsor Park, Belfast on 14 October 1933 in a British Home Championship match.
His second and final appearance for England came in a 2–1 defeat to Wales on 15 November 1933 at St James' Park, Newcastle upon Tyne.
[4] After the war and retiring from playing, Allen became a sports and welfare officer for a Birmingham company, but in 1948 took up the opportunity to manage Colchester United.
On 3 June 1950, with the expansion of the Third Division South, Colchester were elected to the Football League for the first time in their history under Allen's stewardship.