The unfortunate defender has only recently returned to action after three months out with a knee injury, but he has now suffered ankle ligament damage and is expected to be missing until the New Year.
Midfielder Lloyd James will probably revert to right-back in Murty’s absence, although centre-half Wayne Thomas could also fill in.
Saints are boosted by the return of Senegalese striker Papa Waigo, who missed last weekend’s win at Walsall with a back injury.
Waigo will be on the bench with in-form duo Rickie Lambert and David Connolly starting in attack.
Bartosz Bialkowski continues in goal with club captain Kelvin Davis recovering from a groin injury.