On-loan Torquay United pair Ali John and Lloyd Kerry have returned to Charlton and Sheffield United respectively after suffering injuries.
Winger John has a hamstring problem, while Kerry has a foot injury and will now miss the rest of the season.
Director of football Colin Lee said: "Lloyd had been playing very well. When he came on on Saturday, he went over on his foot and now he's out.
"Ali won't figure again. He had done well and was improving all the time."