Louis van Gaal believes Manchester United have been at their best at the start of the 2015-16 campaign when they've been without the ball.

The Dutchman believes his side have been more effective as a defensive unit and insists it is vitally important the Red Devils reach the Champions League group stages

United are unbeaten in their opening four games of the new season although scoring goals has proved problematic, with Van Gaal's side only managing two in the Premier League thus far.

Wayne Rooney's form has been called into question, with the England captain having failed to score for United since April, and Van Gaal believes it is his defensive players who deserve the most credit.

When asked what has pleased him most about his team this season, the Dutchman told reporters: "Until now, of course, our defensive organisation.

"I divide football in to four main moments and we have two moments where the opponent has the ball and then we are at our best, I think.

"We proved that last year and now we are continuing with a lot of clean sheets so that is very important. But we have to improve when we have the ball.

"We have been a little bit unlucky. Liverpool and Arsenal was 0-0 on Monday but you can't say they didn't create anything."

Asked about Wednesday's crunch Champions League meeting with Club Brugge, Van Gaal added: "Yes, [this is United's most important match]. It's been our aim for more than a year to be in the Champions League and still we are not yet participating.

"It's very important. We have to play the game and finish with more goals than our opponents. Then we will be in it."