I have been critical of my old club Manchester United under Louis Van Gaal this season and I have to say that I did not see this change in fortune coming. To the extent that when they go to Chelsea on Saturday, I think they have a good chance of winning the game.

When I look back on the key changes, I still feel that Angel Di Maria’s red card against Arsenal was critical in allowing Van Gaal to build this new-look team. When I look at the side it seems to me to be a triumph of the underdog - Juan Mata, Marouane Fellaini, Ashley Young. All of whom looked like they could be out the picture at the start of the season and are now having a big impact.

The formation is bold. It is much more attacking and more what I expected of Van Gaal when he arrived. There is a spine of four players - Michael Carrick, Ander Herrera, Fellaini and Wayne Rooney - that runs through the middle. Then Young and Mata wide. I wonder whether Carrick will be fit to start against Chelsea on Saturday, which might mean Daley Blind moving back into midfield.

For all the attention after the derby win over Manchester City on Fellaini and Young, a lot of the credit has to go to Mata. He has given United such composure. He is not a winger, in the conventional sense, but he comes inside and gets involved in the game. He always passes to a red shirt and he is so cool, as you saw with his finish against City.

Player Ratings: Manchester United v Manchester City 20 show all Player Ratings: Manchester United v Manchester City 1/20 Antonio Valencia: 7 With Mata drifting infield he kept the right-flank comfortably under control. Always dangerous going forward but it was his defensive covering that impressed today. Getty 2/20 Chris Smalling: 6 He is still prone to brainless moments, as when he was caught in the middle of the park bringing the ball forward, but his goal capped off another solid display. GETTY 3/20 Daley Blind: 7 United kept attacking down the left because of the danger Blind brought through fine deliveries and a great understanding with Young. getty images 4/20 Michael Carrick: 7 A solid, composed performance, keeping possession throughout and stepping back to help out in defence. Exactly what Louis van Gaal would have wanted from his vice-captain. getty images 5/20 Ander Herrera: 8 The Spaniard is fast becoming the all-round midfielder United have been searching for for a decade. He brought a strong passing range and confident dribbling to United’s victory. getty images 6/20 Ashley Young: 9 He deserved the lucky break for his goal as he put in an excellent performance on the left. His cross for Fellaini’s goal would have made David Beckham proud. 7/20 Wayne Rooney: 6 For once the captain was peripheral in a Manchester derby, though he was still able to produce an assist for Mata and combine well with Fellaini. GETTY 8/20 Marcos Rojo: 6 He couldn’t have asked for an easier assignment than 15 minutes against a shell-shocked City. A quiet afternoon for the Argentine. getty images 9/20 Joe Hart: 4 Should have done much better with both United’s goals, in particular letting a soft Fellaini header through him. 10/20 Pablo Zabaleta: 5 Was given a torrid time by Young, so concerned was he that he rarely if ever ventured forward, leaving his side light on attacking promise. Getty 11/20 Vincent Kompany: 3 His first booking for diving in on Blind showed a man off the pace, it was little wonder he was taken off at half-time. 12/20 Martin Demichelis: 4 Provided no support for full-backs when Fellaini consistently peeled off to the back post, showed no leadership or organisation after Kompany went off. Getty 13/20 Gael Clichy: 4 Switched off to allow Young to ghost in for United’s first and didn’t switch back on again after. Too often he left space out wide for Valencia to attack. Getty 14/20 Yaya Toure: 4 An anonymous presence who did little in either box and was overrun in the middle of the park. His defensive deficiencies are becoming more pronounced in each big match he plays. Getty 15/20 Fernandinho: 5 Out-skilled and out-thought by Herrera and co, never more so than when a quick change of feet by the Spaniard left the Brazilian on the floor. Getty 16/20 Jesus Navas: 5 His crosses seemed to be City’s best outlet as United grew in confidence, however he too often left Zabaleta alone to defend the right flank. Getty 17/20 David Silva: 6 Another who started brightly, but the manager’s decision to station him out on the left backfired as he was unable to get on the ball and influence the game. Getty 18/20 James Milner: 5 His reverse-pass to Silva created the first goal but after that he began to make atypical mistakes. Pellegrini was right to replace him with Nasri. Getty 19/20 Sergio Aguero: 7 Took his early goal smartly but was left without support or creativity behind him. When he was given an opportunity, he took it. Getty 20/20 Eliaquim Mangala: 4 Fluffed his chance to impress when his captain came off at half-time, the £40 million defender seems to struggle with skills as basic as positioning relative to his colleagues. Getty 1/20 Antonio Valencia: 7 With Mata drifting infield he kept the right-flank comfortably under control. Always dangerous going forward but it was his defensive covering that impressed today. Getty 2/20 Chris Smalling: 6 He is still prone to brainless moments, as when he was caught in the middle of the park bringing the ball forward, but his goal capped off another solid display. GETTY 3/20 Daley Blind: 7 United kept attacking down the left because of the danger Blind brought through fine deliveries and a great understanding with Young. getty images 4/20 Michael Carrick: 7 A solid, composed performance, keeping possession throughout and stepping back to help out in defence. Exactly what Louis van Gaal would have wanted from his vice-captain. getty images 5/20 Ander Herrera: 8 The Spaniard is fast becoming the all-round midfielder United have been searching for for a decade. He brought a strong passing range and confident dribbling to United’s victory. getty images 6/20 Ashley Young: 9 He deserved the lucky break for his goal as he put in an excellent performance on the left. His cross for Fellaini’s goal would have made David Beckham proud. 7/20 Wayne Rooney: 6 For once the captain was peripheral in a Manchester derby, though he was still able to produce an assist for Mata and combine well with Fellaini. GETTY 8/20 Marcos Rojo: 6 He couldn’t have asked for an easier assignment than 15 minutes against a shell-shocked City. A quiet afternoon for the Argentine. getty images 9/20 Joe Hart: 4 Should have done much better with both United’s goals, in particular letting a soft Fellaini header through him. 10/20 Pablo Zabaleta: 5 Was given a torrid time by Young, so concerned was he that he rarely if ever ventured forward, leaving his side light on attacking promise. Getty 11/20 Vincent Kompany: 3 His first booking for diving in on Blind showed a man off the pace, it was little wonder he was taken off at half-time. 12/20 Martin Demichelis: 4 Provided no support for full-backs when Fellaini consistently peeled off to the back post, showed no leadership or organisation after Kompany went off. Getty 13/20 Gael Clichy: 4 Switched off to allow Young to ghost in for United’s first and didn’t switch back on again after. Too often he left space out wide for Valencia to attack. Getty 14/20 Yaya Toure: 4 An anonymous presence who did little in either box and was overrun in the middle of the park. His defensive deficiencies are becoming more pronounced in each big match he plays. Getty 15/20 Fernandinho: 5 Out-skilled and out-thought by Herrera and co, never more so than when a quick change of feet by the Spaniard left the Brazilian on the floor. Getty 16/20 Jesus Navas: 5 His crosses seemed to be City’s best outlet as United grew in confidence, however he too often left Zabaleta alone to defend the right flank. Getty 17/20 David Silva: 6 Another who started brightly, but the manager’s decision to station him out on the left backfired as he was unable to get on the ball and influence the game. Getty 18/20 James Milner: 5 His reverse-pass to Silva created the first goal but after that he began to make atypical mistakes. Pellegrini was right to replace him with Nasri. Getty 19/20 Sergio Aguero: 7 Took his early goal smartly but was left without support or creativity behind him. When he was given an opportunity, he took it. Getty 20/20 Eliaquim Mangala: 4 Fluffed his chance to impress when his captain came off at half-time, the £40 million defender seems to struggle with skills as basic as positioning relative to his colleagues. Getty

When I was coaching under Ryan Giggs at the end of last season, we always felt that Fellaini’s best position was as an unorthodox No 10 - the role he is playing now. When he first joined United, David Moyes had played him as a central midfielder but I don’t think controlling the game from there is Fellaini’s biggest strength.

When I played against him when he was at Everton, he was just a giant nuisance: elbows up, big and strong and always liable to peel off and take up a position at the back post. That is how Van Gaal is playing him now and not asking Fellaini to do the things he finds more difficult. I do wonder whether Fellaini has the quality to win games in the Champions League latter stages but that is for another day. I always found him a good, committed player who trained hard.

As for Young, I imagine he has benefited from Ryan Giggs’ belief in wide players. At United, we like to have wingers who give the team width and pace. You instinctively look for them and with Di Maria out, Young has his confidence back.

I’m only guessing but I think the poor results and performances have given Ashley more freedom. In the past he has been the focal point for criticism but in recent months there has been so much of that he has been able to get on with his game while others have been in the spotlight. He has got back to what he does best - getting a yard on a defender and crossing the ball early. It’s been a benefit to Rooney as well as Fellaini.

Amidst all this revival spirit I should point one thing out. United are putting the results together now with the pressure off, to a large extent. They are too far off in the title race - barring a total collapse from Chelsea - and the only thing to play for is a Champions League place. How many times over the years have we seen Arsenal turn on the form to get their top four spot at the end of the season when they have no chance of winning the title?

It is all well and good being strong in the last three months. The really serious teams are in there from the start and they get stronger before Christmas and then into the run-in. There is a big difference between title form and a late surge for a Champions League place.

The bigger the game, the more risks Luiz seems to take

I do wonder whether the bigger the game is, the more the risks that David Luiz decides to take. Against Chelsea at Stamford Bridge in the previous round of the Champions League he was excellent. Then against Barcelona on Wednesday he was a defensive disaster. What you need from a defender is reliability and consistency and, for all his good games, it is the mistake waiting around the corner that would terrify a manager.