"It's a blow because it's worse than we initially thought."
The midlands club are still without striker Gabriel Agbonlahor, following surgery on a groin problem.
But fellow striker Emile Heskey and winger Marc Albrighton - who were ruled out of the Chelsea clash with a back injury and sickness respectively - and also defender Richard Dunne (ankle) look like winning their battle to be fit for Saturday.
"Richard has trained normally, Marc returned to training on Monday and Emile is much better and has trained normally," revealed Houllier.
"As for Gabby, I hope at some stage next week he may be able to train. He won't be involved this weekend."
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.