Southampton boss Ruben Selles says “every manager should learn” from Erik ten Hag’s decision to back his Manchester United players who were humiliated at Liverpool.

United’s 7-0 Anfield annihilation equalled their heaviest ever defeat, an embarrassment brought into even sharper focus as it was inflicted by their great rivals.

Yet four days later, Ten Hag named the same side for the Europa League tie with in-form Real Betis and was rewarded with a handsome 4-1 victory before next week’s last-16 second leg in Spain.

“They will try to build momentum after that difficult moment in Anfield,” Selles said ahead of Southampton’s visit to Old Trafford on Sunday.

“I think it’s difficult to manage those kind of moments and Erik did a really good job there.

“I expect them to make some rotation in the line-up, because it’s not easy to play every three days.

“But as we can see, he made a correct decision to stay with his players and I think every manager should learn that lesson from him.”

A few days before his first game in charge – the shock 1-0 win at Chelsea – Selles sat down with his backroom staff to watch the Blues take on Borussia Dortmund in the Champions League.

The practice was repeated on Thursday when United met Betis.

Selles said: “We are using those events to have dinner with the technical staff and watch it together. To analyse the game but also to have some relaxing moments together.

“They started really solid and scored the goal, then Betis tried to apply high pressure and put them in trouble. They had some good moments, scored the goal, and potentially could have made it 2-1.

“Manchester started the second half as they have been doing the whole season, in the second part of the game they were very strong.

“They came back from the dressing room with clear ideas, make a couple of substitutions and are even better than when they start.

“I think the game was a clear example of what they are. Erik has changed his approach since the beginning of the season.

“He tried to implement the same style he had at Ajax, which was really successful and an example across Europe.

“It’s not easy to implement the philosophy from the beginning, he adjusted his style and since he tried to play a little bit more direct I think he has been more successful

“I think they have an identity now and he’s building a strong team.”

Selles, appointed last month after Nathan Jones’ dismissal, has overseen two wins and one defeat in the league.

All three games have finished 1-0, with victory over Leicester last weekend lifting Southampton off the foot of the table for the first time since before the World Cup break.

Selles said: “A lot of games this season in general have been decided by one goal and that makes the marginal gains so important.

“We want to get those marginal gains on our side and that’s what happened against Chelsea and Leicester.

“If we can keep games tight we can be there, we can perform and give ourselves the chance to win.”