Roy Hodgson is under no illusions as to how difficult it will be for Fulham to preserve their 100% record when they take on Chelsea.
The Cottagers go in to this weekend's derby full of confidence having registered two Europa League qualifying wins over Vetra, one over Russian side Amkar Perm and another in the league against Portsmouth.
Hodgson admits, however, that Fulham will have to up their game considerably if they are to have any chance of beating title contenders Chelsea and said: "It's a very tough game for us because it's a local derby and they are a team who don't lose very many in the course of the season."
He added: "Everyone seems to think Chelsea this year will have a very good chance of challenging Manchester United and Liverpool for the title with Arsenal as slight outsiders in that group of four.
"When you are playing any of those teams either home or away you know you've got a real tough challenge on your hands.
"We've won all our matches so far and have only conceded one goal which is very satisfying but we know that out of those matches we have played none have been in the top four and we do know that when we do face one of those top four, we will be sorely tested.
"We'll have to play better than we have done in our last four games because the opponent is certainly a step or two higher than the opponents we have faced so far."
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