Simpson spent time with Norwich, Gillingham and Cambridge City before
joining Diss in the summer of 2001. He "provides good strength
to the midfield"
In August 2004, Gareth switched to Ridgeons League rivals Needham
Market but moved to Mildenhall shortly afterwards.
In January 2008, Gareth signed for AFC Sudbury
He was loaned to FC Clacton in August 2008
Gareth signed for Wroxham in June 2009 but did not sign again for
the following season. He then joined Norwich United.
He moved back to Mildenhall in the summer of 2015.