Carlisle manager Greg Abbott is waiting to learn the full extent of the injury sustained by Mike Edwards at Swindon.
Centre-half Edwards was forced out of the action in the eighth minute with hamstring trouble and Abbott's side went on to lose 4-0, their seventh defeat in their last 10 league matches.
"The injury to Mike came at a bad time, but we had Peter Murphy ready to go," Abbott told the club's official website.
"He felt something with his hamstring, but it's too early to say what exactly has happened, so we'll keep a close eye on that.
"Hopefully it will be nothing too serious because we want as many fit bodies available for us as possible."
Abbott is hoping midfielder/defender Chris Chantler will return to contention for Sunday's home league game with Coventry.
"We felt we needed to give Chris's ankle a bit of a rest," Abbott added.
"Matt Robson can do that job and this period of time will do Chants the world of good. I'm sure he'll come back raring to go."