Van Gaal wants complete performance

United needed a 94th-minute equaliser to scrape a draw against Chelsea in October, but the team have improved so much since that ending the Blues' unbeaten home run on Saturday would come as no surprise, even though Van Gaal may have to drop Wayne Rooney into midfield due to an injury crisis.

Van Gaal's men have moved within eight points of the Barclays Premier League leaders after six successive wins, the latest coming last weekend when they thumped Manchester City 4-2.

After nine months at the helm, everything is starting to click for Van Gaal.

Champions League qualification looks all but assured, attractive football has returned to Old Trafford and the United players have started to get to grips with Van Gaal's much-publicised philosophy,

But being the perfectionist he is, Van Gaal still thinks there is room for improvement.

"We are progressing and playing more like a team," the United manager said.

"There is more balance. I do believe that we can play very well but we haven't played very well for 90 minutes.

"First we have to play 90 minutes very well. Against City we didn't manage that because the first 15 minutes was not good."

Van Gaal has taken encouragement from the fact that his United team seem much more comfortable playing against their top-four rivals, which is apt given that Chelsea, managed by his former protege Jose Mourinho, have not lost at home in the league for almost a year.

David Moyes could only manage one victory against top-four opposition last year - that came against Arsenal in November.

But his successor has lost just once against their Champions League rivals - versus City at the Etihad Stadium.

Van Gaal puts the improvement down to a better understanding of his philosophy.

"It's because they know why they have to play in a certain way," he said.

"You are capable but unconscious and I want them to be capable and conscious. Then, at the end, they are unconscious-capable, that they are doing it from their stomach.

"Now we have reached the point they're doing it as a team, not as an individual because football is a team sport, so that is the difference."

The Dutchman still has reservations about United's ability to beat teams from lower down the table who park the bus against them.

"We have a big deficit in height," he said.

"When you speak with a basketball coach one or two centimetres is very important.

"In football it is the same because a third or quarter of the goals come from set-plays."

Chelsea will provide United with perhaps their toughest physical test of the season as they look to move 10 points clear at the top of the table and maintain their formidable home record.

Michael Carrick is out for two weeks with a calf injury and Daley Blind is missing with an ankle problem, so Van Gaal is considering playing Rooney as a holding midfield to protect the back four from stars like PFA player of the year nominee Eden Hazard.

Van Gaal said: "Blind and Carrick could play in the holding midfield position, and I don't have another option or I have to play Wayne Rooney again in that position."

Radamel Falcao, James Wilson or Marouane Fellaini will lead the line as Robin van Persie is not match fit after two months out with an ankle injury, Van Gaal said.

Phil Jones, Marcos Rojo and Jonny Evans are also out so Chris Smalling will have an inexperienced partner alongside him in central defence.

Paddy McNair has begun 11 games for United and Tyler Blackett has not started a league game since November, but when asked if he had any reservations about either player Van Gaal responded in a blunt if somewhat confusing manner.

"That's also a truth like a cow," he said.

"That's a Dutch expression - it means a rhetorical question. You know the answer already."

Van Gaal gave Mourinho his first break in coaching at Barcelona 18 years ago.

The Portuguese's touchline antics and comments in the media have annoyed many in the game, but Van Gaal thinks his extremely successful coach is somewhat misunderstood.

"He's a modest guy and no-one can imagine that. That's a pity," he said.