Carlisle boss Greg Abbott will assess the fitness of Lubo Michalik before deciding if the on-loan Leeds defender will face Charlton.
The big Slovakian, who has missed the last three matches with a hamstring injury, was able to train on Thursday.
Abbott rates Michalik as a major doubt but has stopped short of completely ruling him out. Peter Murphy will continue if Michalik fails to make it.
Mike Grella is in contention for a place in the starting line-up after an impressive debut off the bench in last weekend's 2-1 defeat to Exeter.
Winger Matty Robson, who scored United's goal in Devon with a superb 35-yard free-kick, is also pressing for a place in the team.
Charlton will be without Kyel Reid when they travel to Carlisle.
Winger Reid is facing up to four weeks on the sidelines after suffering ankle ligament damage against Brighton last weekend.
Scott Wagstaff, who is fully fit after a foot injury, Lee Martin or Johnnie Jackson will fill in on the left flank.
Boss Phil Parkinson is considering further changes following the 4-0 drubbing by the Seagulls and could hand a recall to midfielder Alan McCormack after he recovered from a calf problem.
Full-backs Simon Francis, Matt Fry and former Carlisle forward Joe Anyinsah are also pushing to be involved.
Akpo Sodje, Kelly Youga (both knee) and Chris Solly (ankle) remain on the sidelines.