John was a former England Schoolboy International goalkeeper and was at Luton Town as a youngster. He had already played for North Harefield, Hillingdon Borough and Hendon, amongst others, before joining Northwood for the first time in April 1980, making his debut in a 1-0 Hellenic League defeat at Forest Green Rovers.

His work with the RAF took him abroad in 1983 but he returned three years later and again made the goalkeepers jersey his own until retiring in 1989. He became goalkeeping coach at the club and would also have spells as first-team coach and assistant manager, once having to don the gloves again at the age of 45 during a goalkeeping crisis.

John gained many representative honours, including Combined Services, R.A.F., Middlesex County, and various leagues.