Edwards and fellow centre-half Murphy have both missed the last two games due to respective hamstring and calf injuries.
Manager Greg Abbott must decide whether to recall either player to his starting line-up or retain Danny Livesey at the heart of his defence alongside recent signing Sean O'Hanlon.
Left-back Chris Chantler remains doubtful due to a sprained ankle, so winger Matty Robson is on stand-by again to step into the back four, but Abbott has no other new injury or suspension problems.
Teenage striker David Symington is pushing for a starting place after stepping off the bench last week and salvaging a point for the Cumbrians against Scunthorpe with a terrific strike.
Midfielder Paul Thirlwell and striker Danny Cadamarteri are both expected to be named among the substitutes again following their respective calf problems.M