Defiant Ruben Amorim insists he WON'T change his failing ways at Man United - even as Roy Keane suggests even his players have lost faith in it

Ruben Amorim has once again insisted that he 'won't change' his rigid 3-4-3 system despite Man United slumping to another humiliating defeat. 

After the Portuguese boss pulled off a stunning win at the Etihad Stadium last season, Red Devils fans went into this Sunday's Manchester derby with genuine optimism. 

But they soon found out that United - setup in Amorim's usual system - are still a long way off their Manchester neighbours. 

On a day where Ricky Hatton passed away, it was fitting that City's homegrown star Phil Foden opened the scoring with a placed header into the bottom corner.

United did show signs of promise through Bryan Mbuemo and Amad, but their defence was bullied by a well and truly on-song Erling Haaland from minute one. 

Having narrowly missed the target with an impressive effort on just 18 seconds, the inevitable Norwegian at last got his goal early on in the second half with a deft chip over Altay Bayindir.

And just minutes later he'd bagged his second after some totally lacklustre play from the visitors in midfield gifted Haaland a one-on-one, which he didn't squander. 

Questions were once again asked of Ruben Amorim post-match after another hugely disappointing, and disjointed, display. 

Yet the Red Devils boss, who has just eight Premier League wins during his time at Old Trafford, insisted he will persist with his 3-4-3 formation. 

The former Sporting Lisbon manager said in his press conference: 'I'm not going to change. 

'When I want to change my philosophy, I will change. If not, you have to change the man. We will talk about that every game we lose. I play my way and I am going to play my way until I want to change.' 

Former United captain Roy Keane was one of Amorim's critics post-match, claiming that it doesn't seem as though the coach's players even believe in his methods. 

'We were told the manager needed a pre-season, his own players and they have spent over £200m so we keep making excuses. When are we going to see signs?,' he said on Sky Sports.

'You see Slot going into Liverpool, they end up winning the league and Frank to Spurs, are they improving? Yeah.

'My worry is... maybe the players haven't got that much faith in it. As much as the manager is saying 'this is where we are going', as the results don't come and you are getting beaten by the better teams, he is making loads of changes... it is like they are going round in circles.

'We gave him the benefit of the doubt when he first came in.'

The fixtures don't get any easier for Amorim, with Chelsea - and Alejandro Garnacho - making the journey north to Old Trafford next weekend. 

The Red Devils then face a difficult trip to London to face an in-form Brentford side.