Morrison is a robust centreback who arrived in Wiltshire during the summer of 2007.
After impressive displays for the youth and reserve sides, he was handed a call up to the first team and made appearances against Gillingham and Millwall at the end of the season.
The defender has benefited greatly from the advice passed on from defensive coach Ady Williams, himself a veteran of over 500 professional games which included International outings for Wales.
Morrison made his first start of the season in the Carling Cup encounter against QPR where he lined up against the likes of Emmanuel Ledesma and Dexter Blackstock.
Former Reading defender Callum Kennedy was granted a taste of first team action by former Town boss Paul Sturrock.
The youngster made a surprise start in the 4-1 win over Brentford in the Johnstone's Paint Trophy in September 2007.

Comfortable at left-back, Kennedy was a regular for the Town reserves last term and was taken on the pre-season tour to Austria in the summer of 2008.
The player was handed a chance to impress in pre-season with games against Cardiff City and Plymouth Argyle.
He was also an unused substitute as Town began the League One season with a 3-1 win over Tranmere Rovers at The County Ground.
After being named on the bench against Leicester City in November, Kennedy made his full Town debut against Carlisle United.