Centre-half Cullip had to be replaced after 71 minutes with a hamstring injury, which almost certainly rules him out of Saturday's game.
Curtis picked up an ankle injury during the game, and faces a fortnight on the sidelines.
Scunthorpe's only current doubt is defender Andy Butler, who suffered concussion during Saturday's 1-1 draw with Gillingham but should be fit to play.
Veteran striker Tommy Johnson could make the matchday squad if he comes through a reserve game against Hull on Wednesday, while new signing Billy Sharp is also likely to make his debut at some point during the clash.