Roberts has been out for the past 6 months with a problem with his knee, and has had further problems in the past.
The 28 year old joined Swindon in 2004 from Bristol City, but has had a few problems during his time with the club including being injured in a car crash, knee problems, and been out with a drink problem.
During his 4 years at Swindon he played 88 games, and scored 27 goals, with his best season being 2006/7 where he played 42 times scoring 13 goals.