Berwick rider Hynek Stichauer has been ruled out until early June with ongoing shoulder problems picked up during the meeting against Scunthorpe in April.
The 23-year-old suffered a severely dislocated joint which has been slow to heal despite physiotherapy sessions.
"Hynek will have to wear a specially-designed shoulder brace every time he gets back on his bike," team boss Ian Rae said.
"This will be a permanent requirement until the end of the season."
Rae added: "He will have to go under the knife (at the end of the season) for an operation to make a permanent repair."
Czech rider Stichauer joined the club in January, and has Wolverhampton and Stoke among his former clubs.