He made his first successful team debut on 27 December 1994 as a substitute in an away match at Nottingham Forest, following an injury to first-choice goalkeeper Bryan Gunn.

Gunn was re-instated as first choice goalkeeper at Carrow Road at the start of the following season, and Marshall had loan spells at Bournemouth and Gillingham to increase his first team experience.

However, Marshall's contract was due to expire in the summer of 2001 and he had refused to sign a new deal with the club citing that he wanted to play Premier League football having proved his capabilities.

Marshall joined the then Premier League club Ipswich Town, also the rivals of Norwich City, on a free transfer.

During his time at the club Marshall won many Man of the Match awards and was part of the Millwall side that fulfilled every footballers' dream of playing in the 2004 FA Cup Final at the end of the 2003–04 season.

In the final at Cardiff's Millennium Stadium, Millwall were beaten 3–0 by Manchester United, in which Marshall put in an outstanding performance.

Marshall spent a short period on trial at Queens Park Rangers following his release from Coventry City and the club offered him a one-year contract on 3 August.

[9] On 2 January 2011, following the loaning of Brad Guzan to Championship side Hull City, Marshall was named on the Aston Villa bench in a 3–3 away draw with Chelsea.