Derby were mainstays in the top half of the First Division during Hann's time with the club and he struggled to hold down a regular place in the team.
[6] In the 1938–39 season, Hann was an ever-present in the Derby side playing all 42 league matches and one FA Cup tie.
The following season was cut short due to World War II and Hann's professional league career ended due to the hiatus the war caused to professional football in England.
[2][3] In November 1953, he rejoined former club Derby County as head trainer when former teammate Jack Barker was appointed first team manager and retained this role under subsequent managers Harry Storer and Tim Ward.
[8] Hann described his dismissal as a "body blow" and was reportedly shocked by the announcement, which came despite the players speaking in support of him.