Simpson began his professional career with Lincoln City, having been spotted playing for Netherfield in the Lancashire Combination but only managed five first-team appearances for the Sincil Bank club before Gillingham snapped him up in the summer of 1957 for just £750.
For the next fifteen years he was the Gills' first-choice goalkeeper, helping them win the Fourth Division championship in the 1963–64 season, during which he let in just 30 goals, a club record which stood until 1995–96.
He won the Kent side's Player of the Year award in consecutive seasons (1969–70, 1970–71).
[3] In 1972, after a club record 571 Football League appearances, he left the professional game to see out his career with non-league Maidstone United, but in 1975 he returned to Priestfield Stadium to play for Gillingham's reserves due to an injury crisis.
[2] His record tally of 571 league appearances for Gillingham remains intact to this day, fellow goalkeeper Ron Hillyard's career having been ended by injury just 8 matches short of the record, although Hillyard made more appearances than Simpson in all competitions.