Cripps and fellow top midfielder Adam Cerra (hamstring tightness) will miss Saturday's Marvel Stadium match against West Coast.
It should be clear cut for the Blues, who have won their last four games and are coming off a big victory over Port Adelaide, while the Eagles are last in the ladder with only one success so far this season..
Carlton have also lost Harry McKay (knee) and Jordan Boyd (suspension), but they remain hot favourites.
While coach Michael Voss said the injuries to Cripps and Cerra were "on the minor end", he admitted Cripps had given them cause for concern.
Carlton are only saying the reigning Brownlow medallist has a "cork" and have not specified where the bleeding is.
Cripps will most likely need to pass a fitness test next week.
"Chez (Cerra) wasn't able to finish the game (against Port), so that was a bit more obvious," Voss said on Friday.
"Probably the one that came as a bit more of a surprise was Crippa - the cork bled a little bit more than we would have liked.
"That really inhibited him this week. He hasn't been able to train.
"His last 24 hours, he's settled down a little bit. As of yesterday, he was a fair bit of risk even for next week."
Voss added the Blues medical team had looked at draining the affected area, but decided that was unnecessary.
The injuries to Cripps and Cerra mean fringe midfielder Paddy Dow will be able to stake his claim after only managing four senior games so far this season.
"We feel like he is extremely ready. We don't want him doing any more than what he has been doing," Voss said.
"He has been in really good form, and he knows what it takes to get out there and play well," Voss said.
The coach added despite their run of strong form, which has put Carlton back in finals contention, the team remains a work in progress.
"We still have a lot of work ahead of us and we can't take for granted where we are and what we've been able to do," he said
"We have a laser focus on our next opponents ... West Coast."
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