Although he was said to have played for London side Corinthian Casuals, most of Mervyn's football career had been in the Bristol area with a variety of teams in both Saturday and midweek football. Playing for teams such as Mount Hill Enterprise and Bristol Co-op in the late 1950s, he had also been with Welton Rovers, Trowbridge Town and Glastonbury by the time of his association with Exeter City. Birth records suggest he may have been aged around twenty-seven or twenty-eight.

He later turned out for Cadbury Heath and Chippenham Town and won representative honours for Gloucestershire and the Bristol Midweek League.