Marcus is a youth team product who was released by Norwich in the summer of 1995 without making a single first team appearance. This was somewhat surprising when the 1995/96 Norwich City official handbook had described him as "naturally left-footed and skillful on the ball, he possesses excellent vision and accuracy". He joined Bournemouth but only made 13 appearances before being released at the end of the 1995/96 season.

Marcus joined Dr Martens League side Bashley the following August. In December 1998, Marcus joined Lymington and New Milton but moved to Dr Martens Premier Division side Dorchester Town in August 2000. Over the next three seasons, Marcus made over 90 appearances for the Magpies but made just 11 of those in 2002/03. As a result, Dorchester cancelled his contract in June 2003. He found himself a new home at Wessex Leaguers Wimborne Town, who interestingly are also nicknamed the Magpies.