Simon began his career with Tottenham (3 league matches) and it was from Spurs that he spent a loan period at Carrow Road in 1984/85 although he did not make a first team appearance for the Canaries. He also spent time at Exeter (26 games) before joining Huddersfield for a 118 league game spell in Yorkshire. He moved to Sheffield United and made 37 games for the Blades, scoring 4 times. He returned to London to join Charlton for whom he made 127 league appearances, scoring 7 goals, before joining West Ham. Simon Webster made just 5 appearances for the Hammers and spent time on loan to Oldham (7 games) and Derby (3 games).

Injury problems led to Simon's retirement from the professional game. He was playing for St Albans City of the Ryman Isthmian League but made only 2 appearances during 1997/98.

He trained as a physiotherapist and has worked for Charlton and West Hame before joining Gillingham on 26th March 2004