Manchester United boss Louis van Gaal has admitted the club’s most likely route to next season’s Champions League is to win the Europa League.

United’s 2-1 defeat at struggling Sunderland in Saturday’s early kick-off left them six points adrift of the teams ahead of them before the bulk of the latest round of fixtures, and a top-four finish via the Barclays Premier League now looks a distant possibility.

Indeed, Van Gaal, who has spent recent weeks fending off speculation that Jose Mourinho is being lined up to replace him, believes they may have to look elsewhere for their golden ticket with their Europa League campaign resuming in Denmark against Midtjylland on Thursday evening.

He said: “It will be very difficult. It is still possible, but it is very difficult. The way with the Europa League is easier, I think, but also not so easy because there also you have a fantastic European level in that cup, so you have to fight for it.

“You can easily say ‘ okay, the other way’ — but also you have to show your capacity, in every match, you have to show it and we didn’t do that today.”

Van Gaal’s position becomes more difficult with every setback, and he knows the consequences of failing to make it into the Champions League could be costly.

Asked if the club’s presence in Europe’s elite competition was the bare minimum, he said: “Yes — but that’s also our aim, so you cannot close your eyes from that.

“Today it was very disappointing because we needed to win this game because of the big gap between the top four. We want to be there and now it will be very difficult.”

United started dreadfully at the Stadium of Light and fell behind to Wahbi Khazri’s third-minute free-kick, which travelled across a crowded penalty area without anyone making contact and crept inside David de Gea’s far post.

Anthony Martial’s deft 39th-minute finish got them back on level terms — but they were second-best after the break and were undone when De Gea could only help defender Lamine Kone’s powerful downward header into his own net.

Van Gaal's misery was completed by the loss of full-back Matteo Darmian, who will be missing for several weeks after dislocating a shoulder.

Black Cats boss Sam Allardyce was thrilled with both his side’s performance and the result as January signings Kone and Khazri in particular shone once again.

He said: “It was a really good performance today with the right result.

“Everybody that produced and played on that field deserves a lot of credit today for the way they have managed Manchester United and how often we have taken the game to them and created lots of chances to win this game — and finally got the goal that did win it from Lamine.

“Our new players have made a massive contribution since they have been here, but nothing bigger than today with Wahbi’s goal from the free-kick and then his corner and Lamine scoring the winner for us.

“That hopefully will bode well for the rest of the season.”

Allardyce and his players will now jet off to a warm weather training camp in Dubai with their survival hopes rekindled.

It gives Billy Jones, Younes Kaboul, Sebastian Larsson, Jeremain Lens and Duncan Watmore, who all missed this game through injury — and Jermain Defoe, who passed a late fitness test, time to recover.

He said: “With a result as big as this one, I hope it lifts their confidence brilliantly for the big push to try to get out of the trouble that we are in.”