Following in the footsteps of his father, Alfie, a former Newcastle United, Cardiff City and Tranmere player, Hagan represented England at schoolboy level and after spells with Washington Colliery and Usworth Colliery; he joined the groundstaff of Liverpool before leaving for Derby County at fifteen years of age.

He stayed at the Baseball Ground until the age of twenty when United's manager Teddy Davison met his Derby counterpart George Jobey and haggled over the £3,000 asking price, eventually agreeing to pay £2,925.

[9] He had previously toured Australia with an FA party seven years earlier, scoring eight goals in a match versus Tasmania.

After leaving Peterborough, he joined West Bromwich Albion in 1963 leading the team to the Football League Cup in 1966.

Benfica in Lisbon where he led the club between 1970 and 1973 to three successive Portuguese championships and once to the national cup, a record no coach has since been able to repeat at the helm of the Águias.

[12] In 1972 and 1973, Hagan led Benfica to become the first club in Portugal ever to win the championship without defeats and won 28 matches – 23 consecutively – out of 30, drawing the other two.

In that year Eusébio also became Europe's top scorer with 40 goals, in what was his penultimate season as a Benfica player.

Jimmy Hagan separated from the club in September 1973 after an argument concerning the line-up for the testimonial match for Eusébio.

West Bromwich Albion Benfica Boavista A bronze statue of Hagan by sculptor Kenneth Robertson was unveiled at Bramall Lane on 19 January 2001[18] by the Portuguese football player/manager Eusebio.