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 on Sunday.
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.
"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,'' said Hodgson.
"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.''
The match will be Carlo Ancelotti's first taste of a London derby since taking over as Chelsea boss.
Hodgson knows the 50-year-old from his time spent managing Udinese and Inter Milan in Ancelotti's homeland, and has been impressed with the start that the Italian has made at Stamford Bridge.
"The players seem to have taken to him and his methods. Chelsea have been impressive for the last four or five years whoever has been in charge and they certainly won't be any weaker with Carlo Ancelotti at the helm,'' Hodgson added.
Andrew Johnson will be missing from Hodgson's starting line up having broken his collar bone during Thursday's game.
Hodgson was left seething when the 28 year old had to be replaced after taking a hefty bodycheck from Russian defender Dmitry Belorukov.
The 62-year-old admitted yesterday that he was looking to add a striker to his squad thanks partly to Johnson's injury, but insisted that the former Everton's striker's absence will not greatly affect how he approaches the game.
"We have less options now we have lost Andy but we have front players who can go in for one to ones and midfield players who can play up front so I don't think our general style will change enormously whichever option we choose,'' he said.