Manchester United great Paul Scholes was once again left questioning the club's wisdom in hiring Ralf Rangnick as interim manager after Sunday's 4-1 derby humiliation by Manchester City.

Kevin De Bruyne and Riyad Mahrez got two goals apiece at the Etihad Stadium, as City restored their lead at the Premier League summit to six points over Liverpool.

United – without Cristiano Ronaldo due to a hip injury – started the game well and were good value for their 22nd-minute equaliser by Jadon Sancho, but thereafter it was one-way traffic as Rangnick suffered only his second Premier League defeat in 14 matches.

Despite that record, Scholes cannot get past Rangnick's lack of recent experience in coaching, having only actually been in charge of a team for two of the previous 10 seasons, instead spending much of his time as a sporting director.

Rangnick was hired as Ole Gunnar Solskjaer's replacement at the end of November until the end of the season, at which point he will move into a consultancy role.

The move was initially widely praised as it seemed to suggest United were looking to establish an on-field identity that Rangnick would subsequently be able to influence with big-picture decisions, but Scholes is struggling to see the reasoning behind hiring him as the interim manager.

"What do we expect? We've brought in an interim coach who hasn't coached at an elite team," he told Premier League Productions.

Man City

"He hasn't coached a big team, he hasn't coached at a big football club like United where there's so much expected of Manchester United, whoever you're playing against, it doesn't matter. He's never been at a top club. He's coached a club for two years out of the last 10 years.

"How have United behind the scenes come to the conclusion that this man is going to be the right man for six or seven months? It baffles me. The players are lost on the football pitch.

"The first 20 minutes I was surprised, they played really well, they were comfortable on the ball, [Paul] Pogba up front looked alright. His [Rangnick's] subs have worked the last few weeks don't get me wrong, but it was a deflated team.

"As much as you can have a go at United, they were playing against possibly one of the best teams we've seen. In the second half, the players looked lost. They looked like they didn't have a clue what they were doing."

Prior to the weekend, Rangnick had been praised for improving United defensively. Before Sunday's hammering, they had conceded 10 goals in 13 league games under the German, having let in 21 in 12 with Solskjaer at the helm – only Norwich City and Newcastle United (27 each) had worse records at the time of the Norwegian's sacking.

But Scholes believes their change in fortunes at the back is a red herring, and the data seems to back him up to a certain degree.

David de Gea's saves since Rangnick's arrival have accounted for the prevention of six goals the average goalkeeper would not be expected to prevent, second only to Jose Sa (6.1).

Sa (192) is also the only keeper to face more shots than De Gea (180) in that time as well, suggesting United are not much better defensively than before – they are just relying on their goalkeeper's improved form.

de gea

"They were lucky it's not five or six. Again the goalkeeper, five or six saves," Scholes continued.

"We spoke before the game saying defensively since Ole's gone [Rangnick]'s shored things up – he hadn't. Never in a million years.

"He's kidding himself if he thinks that. The keeper has stopped him from getting batterings for a long time. [Sunday] was exactly the same."