A youth team player, Stewart was released in March 1997. He had impressed Mike Sutton whilst with Yarmouth High School scoring over 40 goals a season but his spell at Norwich's Centre of Excellence was blighted by injury. He had 2 knee operations and one on his Achilles tendon. With Mike Walker and John Faulkner adopting an Ajax style attack throughout all Norwich teams where only one central striker was deployed, Stewart's chances were limited with rivalry from Drewe Broughton, Chris Llewellyn and Adrian Coote. Even Craig Bellamy wasn't deployed as a central striker. In the Youth team that won the South East Counties League in 1996/97, Stewart only managed 16 starts and scored 9 goals. He departed the club in March 1997 after a disagreement.

Stewart had a trial with Cambridge United; a popular destination for Norwich apprentices who never made the first team at Carrow Road (see Phil Chapple, Dion Dublin). However he was disillusioned with football and thought about quitting the game. Instead he joined Great Yarmouth Town in the Jewson Eastern Counties League scoring on a regular basis and had passed the 40 goal tally in March 1998. He states that he is happy playing at this level and doesn't wish to become a professional. Only time will tell if this happens or not.

Stewart went on the transfer list in March 2000 wishing to try something new after a season marred by injury and a goal drought. Yarmouth have agreed to let him go and Wroxham have already shown an interest in obtaining his services but offered less than the £3000 than Yarmouth expected. Diss and Gorleston were also said to be interested. Greg Downs arranged a trial for Stewart at league side Oldham in February 2001 but Latics manager Andy Ritchie opted not to take his interest any further. According to the Non League Paper website, Stewart moved to nearby rivals Lowestoft in mid March 2001.

In June 2005, Cambridge United caretaker manager Rob Newman announced that he would give Roach a pre-season trial following Roach's forty-five goals for Lowestoft Town in 2004/5. Newman remembered Roach from their days together at Carrow Road. Stewart played for Cambridge against Mildenhall on 9th July 2005 and against Ipswich a few days later. He was then returned to Lowestoft but trialled for Kings Lynn on Saturday 30th July 2005 in a 2-1 defeat against a Millwall XI. Stewart signed for Kings Lynn at the beginning of August 2005 but is expected to initially play for their reserves in the Ridgeons League so to gain match fitness and get to know his teammates. He scored twice on his debut in a 5-0 victory over Clacton Town on 13th August 2005.

Stewart returned to Lowestoft a few weeks later but at the end of November 2005, submitted a transfer request. Many clubs were interested but Stewart eventually signed for Leiston who were rumoured to have paid £7000 for him. Roach repaid the investment by scoring ten goals in his first nine games.

Scoring regularly for Leiston, Stewart expressed hope in February 2006 that he might be called up for the Trinidad and Tobago World Cup squad as his father Claudius was born there. Stewart works as a fitness instructor at Caldecott Hall, near Fritton

In January 2008, Stewart returned to Great Yarmouth Town.

In early August 2010, Stewart signed for Norwich United. Yarmouth manager Paul Tong commented "Stewart's a legend and he'll always be welcome at the club as long as I'm here, and I'm sure others. His circumstances changed and you can't blame the lad. It's the end of one chapter and the start of another. We'll miss his quality for sure"