Former Manchester United boss David Moyes has warned successor Louis van Gaal he has to qualify for the Champions league if he is to stand any chance of keeping his job.

The Dutchman, whose future has been under intense scrutiny in recent weeks amid speculation that Jose Mourinho is being lined up to replace him, suffered a further blow on Saturday when his side were beaten 2-1 by lowly Sunderland.

As the final whistle sounded at the Stadium of Light, fifth-placed United were six points adrift of the top four and Van Gaal and skipper Wayne Rooney later admitted winning the Europa League this season could be the easier route to the Champions League.

But Moyes, who knows only too well the price of failure at Old Trafford after his own ill-fated 10-month spell at the helm, has predicted a bleak future for the manager if he does not get there one way or another.

He said: "I knew Manchester United need to qualify for the Champions League. I think Manchester United need to be there.

"They are a club of status and want to be at that level, if not more. They want to be winning it if they can, never mind qualifying for it. That's what happens at Manchester United. It's that level."

Given his own experiences at United, Moyes has sympathy for Van Gaal in his current predicament.

He said: "There's so much media attention on Louis van Gaal just now. When I lost my job, he was lauded by everybody in football - by the media and everybody else. Now many of you are the ones saying he should lose his job.

"If you go to Manchester United, that's what you get. You get an awful lot of media attention. But I still believe I was the right person to take the job."

Asked if he felt he had been treated unfairly by the club in comparison to Van Gaal, however, Moyes was philosophical.

He said: "I know that the reason I lost my job at Manchester United was I didn't win enough games. It's as simple as that."

Van Gaal left Wearside knowing a top-four finish is now a big ask following a damaging defeat on top of Chelsea's late equaliser against his team last weekend.

He said: "It will be very difficult - I have said that also to the players because you cannot close your eyes to that.

"The defeat is of course a big blow. I said we had to win this match because we have to be in the race for the top four positions in the league, and then you have to win these kind of matches.

"But we can only blame ourselves because the aggression of Sunderland was much higher than our aggression and we could not cope with the pressure on the ball in our own half.

"But okay, they can play like that and we know that they want to play like that, but then you have to cope with it."

United were ultimately undone by two set plays with Wahbi Khazri's third-minute free-kick evading goalkeeper David de Gea, who could later only help Lamine Kone's header from a Khazri corner into his own net after Anthony Martial had levelled.

Van Gaal said: "A set-play is always risky because we don't have a very tall team, so we know that in advance and we organise the best header against the best header. But when you lose them in spite of your good organisation, then you are frustrated.

"But we have to play better. Against Chelsea, we played a very good game; today, we didn't play a very good game."