Bristol Rovers are sending Danny Coles to a consultant in order to discover the severity of the defender's knee injury.
The 28-year-old, who missed the majority of last season with a similar problem, did not play in Tuesday's 4-0 loss to Leeds because of the injury.
He will not play against MK Dons this weekend, but manager Paul Trollope does not believe the problem to be too serious.
"There doesn't appear to be any major problem with his knee," he told Rovers' official website.
"While there are obviously a few issues from previous injuries, there doesn't seem to be anything too acute at the moment.
"We are hoping to send him to the consultant he's seen before to get a second opinion. However, the signs are good, and we are hoping that the consultant gives us the news we are hoping for, because at this moment in time it doesn't seem too severe."