Man Utd must prove Champions League credentials - Van Gaal

Manchester United must prove they merit a place in the Champions League last 16 by beating Wolfsburg in their crucial group tie, says boss Louis van Gaal.

The Red Devils will qualify with a win in Tuesday's final Group B game, or if PSV Eindhoven lose to CSKA Moscow.

But PSV will advance if they better United's result in Germany.

"It is very important for the club to continue in the Champions League," said Van Gaal. "We can't rely on the result of the other game."

United are aiming to reach the knockout phase in their first appearance back in the Champions League since failing to qualify for European competition under David Moyes in 2013-14.

After losing their opening tie at PSV, Van Gaal's side have won two and drawn two to leave their last-16 fate in their own hands.

Goals from Juan Mata and Chris Smalling helped them come from behind to beat Wolfsburg 2-1 in the reverse fixture.

"You have to prove yourselves, as a club, as a team and as players," added Van Gaal, who won the competition with Ajax in 1995.

United, who are three-time European champions, will drop into the Europa League if they finish third behind Wolfsburg and PSV.

'Goals will come for United'

Van Gaal's team were booed off after Saturday's 0-0 draw with West Ham at Old Trafford, with home supporters frustrated at seeing their team fail to score for the fifth time in nine matches.

Skipper Wayne Rooney will miss the Wolfsburg trip with an ankle injury, leaving 20-year-old France international Anthony Martial as their only recognised striker.

"When you are creating chances you shall finish those kind of chances," said the 64-year-old Dutchman.

"That's why we have that belief. It's a matter of time and I hope we can prove it against Wolfsburg.

"I have the experience as a manager that the goals shall come."

Injured forward Rooney has stayed in England, watching his former club Everton play Crystal Palace with his son Kai

No pressure on Martial - Van Gaal

Martial scored four goals in his first four matches following his £36m transfer from Monaco in September, but has netted just once in his past 13 matches.

"We have to give him time and that's always difficult when you are playing for a team like Manchester United because the expectations are very high," said Van Gaal.

"But I am very convinced that he will continue with his performances, and that he shall score at the right moment again.

"You cannot expect a 20-year-old player coming to the Premier League to score every week. I didn't expect it either.

"When he came he was accelerating in the start of his campaign at Manchester United. I know that and I have to explain it to everybody because he doesn't need that pressure to score every match."

'Man Utd had better pay attention'

Wolfsburg know they will reach the Champions League knockout phase for the first time with a draw, but coach Dieter Hecking insists his team will not be content to play for just a point.

Last season's Bundesliga runners-up will finish as group winners if they beat United.

"We want to win, and I think my players want to win too. We pay attention to a lot of things, but Manchester United had better pay attention to us," said Hecking.

"I don't feel any pressure, I am just really looking forward to this game and I know my team will do all they can to make history.

"We've not considered progressing with a draw."

Wolfsburg are currently fifth in the German top flight and boast a formidable record at the Volkswagen Arena, where they lost for the first time in 29 home Bundesliga matches on Saturday, an injury-time defeat by Borussia Dortmund.

And Wolfsburg's former Chelsea forward Andre Schurrle says it is important to score first against United to boost their chances of avoiding another defeat.

"If we can get it, then psychologically it will be good for us because we'll get a little bit more space," said the 25-year-old Germany international.

"It's going to be difficult to get the ball so we have to be very aggressive.

"This is a great game - we are going to give everything we can, really go for it."