An ex England youth international midfielder Glenn had played at left back as an amateur for Chelsea and Wolves and after unsuccessful trials with several clubs was on the verge of quitting the professional game before Gillingham signed him in December 1972. He starred in the Gills 1973-74 promotion campaign before joining the Southern League Dons on a free transfer in September 1974.

A bit part player as Allen Batsford's men won the first of their three successive titles he had become a fixture in the Dons midfield by the time the club were elected to the Football League in the summer of 1977. But having played in the opening Fourth Division match against Halifax Town he made only ten more appearances before falling out of favour.

Signing for Maidstone United in January 1978, he played a key role in their 1978-79 FA Cup run before moving onto Dartford, but he left the Darts after telling a joke at an awards ceremony that offended the major. After a short spell at Chatham Town he finished his career at Thanet United. After retiring he became involved in the commercial side at Maidstone before setting up his own advertising agency in Bedford in 1994. He returned to football from 2002 until 2004 with spells as assistant manager of Whitstable Town and chief executive of Gravesend & Northflee, then in 2010 he was involved with a bid by the Lashings World XI cricket club to take over Maidstone United.

Years Team Apps (Gls)
1972-1974 Gillingham 23 (0)
1974-1978 Wimbledon 80 (7)
1978-1981 Maidstone United
1981-? Chatham Town
?-1984 Dartford
1984 Thanet United 4 (0)