Former Manchester United captain Roy Keane branded their display in the derby defeat by Manchester City "shameful".
Kevin De Bruyne and Riyad Mahrez both scored twice as City condemned their rivals to a humbling 4-1 loss.
There was a party atmosphere around the Etihad Stadium as Pep Guardiola's reigning champions ran amok against their neighbours, regaining their six-point advantage over second-placed Liverpool.
"I think the worst thing you could say about United is they did give up," Keane told Sky Sports. "For a player in a derby, or any game, to give up, it's unforgivable really.
"The beauty of top-level sport is there is no hiding place. We saw all United’s shortcomings today.
"There are ways to lose football matches, we’ve all lost football matches, but the way United lost today... They stopped running. They gave up. There’s players out there not running back.
"That’s what I don’t understand. The manager will be criticised, and the tactics, but players not running back when they are playing for Man United is unacceptable.
"They threw the towel in, which is shameful.
"I forgive mistakes, but you’ve got to run back. There are five or six players who should never play for Man United.
"It’s shameful. A couple of lads in midfield, (Aaron) Wan-Bissaka, Fred, (Marcus) Rashford came on. I could go on. And City weren’t even at their best. They didn’t have to be.
"They gave up, Shame on them!"
Former United full-back Gary Neville was also scathing in his assessment of their performance.
Sky Sports pundit Neville said: "Manchester United ended that game like an absolute shower. They were a disgrace.
"They came up against a proper team and they’ve been given a proper doing."
Asked what he thought of the character and attitude of his players in the second half, interim United boss Ralf Rangnick said: "To be honest, I didn’t have the impression that they didn’t try.
"But it’s difficult against a team like Man City once you are 3-1 down (against) the best team in possession of the ball on the planet it’s difficult.
"I cannot blame anyone for not having tried and put effort into that game, but it was difficult after the third goal."
Rangnick said "after 28 games you’re as far apart from each team as the table shows" when questioned about the gap in quality to City after this embarrassing defeat.
Pushed on how far the interim boss thinks United are behind City, the German said: "22 points.
"The second half showed that if they are in their momentum and if they are 3-1 up then it is almost impossible to keep them away from your own goal.
"Look, I am still the manager for another 10 games in the Premier League and for hopefully a few more games in the Champions League and it doesn’t make sense now to start some speculations about how many players would we need, on which positions would we need them.
"This is not my issue. Right now it’s about preparing the team for the Tottenham game and after that for a very important game against Atletico in the Champions League.
"Right now, we have to be – and I am – happy with the players that we have. This is clear.
"We lost two, if not three strikers since Christmas, everybody knows (that). Again, this is a fact and we have to deal with it. I am not complaining about that so for us it’s important to look ahead and make sure we develop the team, we have in the last couple of weeks and months.
"We do not always play against Manchester City. We have other teams and we showed that against West Ham and against other teams, like Leeds, that we are capable to win those games and this is my major job in the next two-and-a-half months."
Rangnick’s frustration was clear in the post-match press conference and extended beyond those on display, with Edinson Cavani and Cristiano Ronaldo unavailable through injury.
But it is hard to say how much difference the veterans would have made at the Etihad Stadium, where even demanding Guardiola was sated by the second-half display.
"Well, if the second half is not our best I don’t know what we have to do, honestly," the City boss said. "I’m such a demanding man, but I know my limits and I know the players’ limits and the second half in all terms (was excellent).
"United were eight games without defeat, we had I don’t know how many shots in the second half, so the display was excellent.
"I think everything is difficult, everything is complicated. The opponents are so good and today, especially in the second half, we make an excellent performance.
"I’m the biggest critic to my team, but when we play good, we play good and today we played really good."
