It won't be that long....initially they thought they would leave him out of Frankfurt to let it heal, but on Friday last week the medics said he would need to miss a further two, as they can't stitch it properly and that is how long it will take to knit. If he's not there against Blackburn then I'm sure he'll be fine for Chelsea.
Depending on what we get from Blackburn I personally would be tempted to give him one more game off to make sure it's fine as I can't see us getting much from Chelsea anyway. We'll see.