Bradley Dack will miss out as Gillingham prepare to get back to league matters at home.
The midfielder was forced off after just 21 minutes of Saturday's superb 4-0 FA Cup win over Scunthorpe.
Gills have been boosted by the news Dack has not suffered ankle ligament damage although he may possibly have broken a metatarsal, with the full extent and seriousness of the injury yet to be determined.
Charlie Allen and Joe Martin (both wrist) continue to miss out.
Manager Martin Allen made five changes at the weekend but leading scorer Danny Kedwell is sure to return while decisions must be made elsewhere after the positive display.
Allen admits the encounter against former employers Cheltenham, who are third in the table, will the toughest his league leaders have faced this season.
Four Cheltenhams regulars look set to return to the side for the midweek tie.
The Robins ran out 3-0 winners over Yate Town in the FA Cup first round without Steve Elliott, Jermaine McGlashan, Marlon Pack and Darren Carter in their starting line-up and they look likely to be reinstated for the meeting with the club's former manager Martin Allen.
Centre-back Elliott missed training last week due to a bug, team-mates McGlashan and Pack were both named on the bench as manager Mark Yates looked to give two of his regulars a rest while experienced midfielder Carter was targeting this game for a return from his hamstring injury
Carter's absence from Yates' last two starting line-ups has opened the door for Reading loanee Lawson D'Ath but he will not feature after being taken off at half-time on Saturday with a knee injury.
Three points for third-placed Cheltenham would close the gap on Gillingham to four points in what is Yates' 150th match in charge of the club.