McCourt, who had just got himself back in the team, suffered a bad leg injury from a tackle against Solihull Moors last month.
When asked if he will play again this season, Spireites assistant manager Danny Webb said he ‘100 per cent’ would and that he is running again.
Croll suffered a knee injury against Stockport County in February but he is making good progress.
Webb told the DT: "I think Crolly is much more of a yes than a no (on whether he will play again this season).
"I think he had some good news about his injury the other day - it is not as bad as first thought.
"Crolly is not back running yet, but the knee brace is off and he will be jogging next week.
"I think by the end of the season we will have at least those two (McCourt and Croll) back.
"We want to push for the number one spot but if it isn’t to be then we want to be as strong as we can for the play-offs.”
Meanwhile, Manny Oyeleke, who tore his calf against Weymouth last month, is a ‘couple’ of weeks away.
"The manager does not want to rush people back,” Webb explained. “They might be good for an hour of a game but then you might lose them for the next 10. That is the manager’s experience coming into play.”
And Tom Denton will be ‘no more than a few weeks at most’ with an ankle problem.