Manchester City’s inability to adapt to a losing situation away from home is incredible and hasn’t shown any sign of improving. They have never recovered from a half-time losing situation on their travels under Manuel Pellegrini. That’s a shocking statistic. Half-time is the occasion when you see what a manager has got and how good he actually is.

He will need to show a lot more pragmatism and flexibility in this weekend’s Manchester derby or it could end badly for City. We’ve talked here before about the way that City allow both of their full-backs to go upfield at the same time and can also lack the discipline of leaving a midfielder back, causing the centre-halves to be exposed. On the ball City are fine. It’s when they are out of possession – and need some discipline – that these fatal flaws reveal themselves. Those flaws could be amplified this weekend by the fact that United have found a very definite way to succeed, by making very specific tactical use of Marouane Fellaini.

The Belgian has been a massive element in the way that Louis van Gaal has finally found a successful system. Watch his positioning carefully on Sunday and you will see that for the first 25 or 30 minutes he will go right up at the top of the team – as high as, or even higher than, Wayne Rooney – to stretch the opposition, force their defence back and create room and time for the players who are operating behind him. Look at United’s winning games against Aston Villa and Liverpool and you’ll see exactly what an effect Fellaini had, creating space for his team-mates.

Manchester United vs Manchester City combined XI Show all 11 1 /11 Manchester United vs Manchester City combined XI Manchester United vs Manchester City combined XI GK: David De Gea Joe Hart is getting back to his very best but the Spaniard has been the form goalkeeper in the Premier League this season. Behind a dodgy defence De Gea has performed heroics for Van Gaal on numerous occasions. GETTY IMAGES Manchester United vs Manchester City combined XI RB: Pablo Zabaleta Zabaleta is not the guaranteed starter he once was, with Bacary Sagna playing more often since the turn of the year. We're not sure why as the Argentinian is far superior to the Frenchman and a real driving force for this team. Antonio Valencia is not a right-back and could be a weak link City wish to exploit. Getty Images Manchester United vs Manchester City combined XI CB: Martin Demichelis Vincent Kompany is the big name absence from this combined XI. Obviously the Belgian is the best centre-back either side can field but he is performing nowhere near his best. Demichelis gets a bad rap but he has actually been pretty reliable for City, although he is prone to the odd clanger. Manchester United vs Manchester City combined XI CB: Marcos Rojo Chris Smalling's recent form would have seen him in this team but injury while on England duty means he remains a doubt. Phil Jones is too unreliable leaving Rojo as the only other option. He has been decent if not outstanding since his arrival and Van Gaal desperately needs an upgrade at the position. Getty Images Manchester United vs Manchester City combined XI LB: Daley Blind Looks much more effective as a left-back than he does in the middle of midfield, the Dutchman is a stout defender and good going forward. Both Gael Clichy and Aleksandar Kolarov have severe limitations, especially on the back-foot. Manchester United vs Manchester City combined XI RM: Juan Mata How he was out of the side for so long will remain a mystery. Mata might be weak and a bit of a liability defensively but he is one of the cleverest and most gifted players in the world. Jesus Navas has shown flashes but never really impressed for a long spell since his move to City. Getty Images Manchester United vs Manchester City combined XI CM: Michael Carrick You don't know what you've got until it's gone. Carrick has his share of critics but the stats speak for themselves; United have lost 29 per cent of their games with Carrick out of the team and only seven with him in it. Yaya Toure scored just his second goal of 2015 on Monday and is one of the biggest disappointments of the season considering his great form last year. Getty Images Manchester United vs Manchester City combined XI CM: Ander Herrera After a perplexing spell out of the team, Van Gaal has finally decided that Herrera is his best midfield option. Offers drive, great vision and combative tackling next to Carrick and more than capable of chipping in with a goal. Fernandinho can be good on his day but again lacks any kind of consistency. Getty Images Manchester United vs Manchester City combined XI LM: David Silva Manchester United's first priority will be to stop the brilliant Spaniard - do that and you are halfway to beating City. Ashley Young is Manchester United's most improved player this season and a real threat on the left but Silva is a maestro. Getty Images Manchester United vs Manchester City combined XI ST: Sergio Aguero Aguero scored 19 goals before his injury and only four since returning. The goals have dried up and so has City's title threat. Despite his desperate form and lack of fitness he is still one of the best around. Marouane Fellaini had found his worth as a bruiser for Van Gaal but he too has limitations. GETTY IMAGES Manchester United vs Manchester City combined XI ST: Wayne Rooney Since he moved back up front he has six goals in his last eight matches and has proved to Van Gaal just what he was missing. Rooney is in red hot form and will be Manchester United's main goal threat on Sunday. Edin Dzeko has struggled all season and Wilfried Bony has been injured since his arrival. Getty Images

It was no surprise that Juan Mata and Ander Herrera scored twice in those games, using the extra time generated for them on the ball. When Fellaini has had the desired effect, putting defenders six yards further back, he’s then been reverting to a deeper-lying role of his own. There’s an adage for this strategy in football: “You’ve got to go long to come short.”

United are going to feel very confident about picking up the balls that Fellaini’s aerial presence can create for them if City’s full-backs have put themselves out of the occasion by going up together, in the way that they do. That’s why I predict that the Manchester derby will be all about the battle to win the second ball.

When Vincent Kompany and Fellaini go up for a ball, there is a very good chance that it will be bouncing 20 or 25 yards from goal. If Herrera or Mata pick up that second ball there will be a very real threat for City, because those players will be within shooting distance. If the ball falls to whoever City have in the defensive midfield roles – perhaps Fernando or Fernandinho – then it will be critical that they deal with it precisely and effectively. Too often we have seen those players ball-watching, or taking up the wrong positions, allowing gaping spaces to open up. This weekend, they are going to have such important roles.

If City can reveal the rigour and discipline to deal with this situation, then they can create the opportunity to make something out of the game for themselves. Psychologically, they know very well what beating United feels like now and I don’t believe for a minute that the conjecture about Pellegrini’s future created by Monday’s defeat to Crystal Palace will affect them. Players react far less than you might think to an abundance of headlines like that. But it is time to show proper tactical application rather than this blasé assumption that they will play the City way, whoever they are up against.