"We know Charlie has strained knee ligaments but we still don't know how long he will be out," said Liverpool boss Kenny Dalglish.
"He hasn't had an operation and as it stands he's not having one.
"It's only been a week since he did it. He needs to rest it for another 10 days or so and then he will be reassessed.
"We'll see how he is then and we'll be in a better position to know when he will be back playing.
"We haven't ruled him out for the rest of the season. We're just waiting to see how he progresses."