It is fair to say that Manchester United were out-cla sed, out-played and torn to pieces by Arsenal in the first half of their performance at the Emirates Stadium three weeks ago. But if anyone understands football enough, then it is pretty obvious as to why that happened. Carlos Davis Jersey LVG said in his post-match pre s conference, When you give a team like Arsenal so much space to play football then you know you will lose. But why did Man United allow that to happen? No pace. United simply had now pace to cope with Arsenal. The Managers team selection was completely wrong. And if they want to win the Manchester Derby on Sunday, its got to change.First, of all it doesnt help that Luke Shaw was injured, but playing a defensive line with Daley Blind as high as they did against an attack force of Walcott and Sanchez then the outcome is obvious. Arsenal capitalised on the space in behind and punished quickly and efficiently. Van Gaals choice to play the laboured pair of Michael Carrick, 34, and Bastian Schweinsteiger, 31, alluded everyone. No pace to keep up with the tricky trio of Cazorla, Ramsey and Ozil. It allowed Arsenal too much time Chris Wormley Jersey on the ball. 20 minutes gone. Game over. There were two players that should have played that would have given United more cutting edge, more energy and would have mounted more pre sure on Arsenal. The first is Ander Herrera. After his Man of the Match performance against Everton last week, he proved that he has the gut, desire Kordell Stewart Jersey and work rate to be a charismatic figure. He was a nuisance in the middle of the park, not giving Everton a moments peace; he carried United to victory. His energy was mi sed against Arsenal and it will be important in the derby this weekend. Roll back the clock to 12th April when the last Manchester derby took place at Old Trafford. United destroyed Man City in a convincing 4-2 victory. The Key man? Fellaini. He terrorised the Man City defence with his aerial dominance and his aggre sion even grabbed himself a goal. That aggre sion is what would have neutralised Arsenal. Fellaini covered 13.12km vs Southampton last season and would have inevitably put more pre sure on Arsenal. If United want Joe Haeg Jersey to beat Man City in the same style this weekend then Fellaini must play, to give United that physical edge. Game time has been limited this season for him but he is always up for the fight.But Fellainis stand-out performance last time out was only due to the a sistance of Ashley Young, another man who will be important this weekend. If he features. His cro sing abilities are dangerously good, whipping it into the box with pace and power, causing a nightmare for any defence. VerdictThe Manchester Derby is the most highly anticipated fixtures of the season. Chelsea may have one the Premier League last season but these two teams have dominated English Football since the last day dramas Jack Lambert Jersey of 2012. And it looks like this will be a crucial fixture in the title race this season.Manchester City are without Aguero and Silva going into this game due to injury. But with Sterling, De Bruyne and Bony all covering, City still look dangerous. Chris Smalling must continue his fine form in order to stop Bony. It comes down to the managers team selection. LVG must play players who are going to work hard and are willing to battle with City. But also players with some added energy like Herrera, Schneiderlin and Fellaini and for this occasion, Schweinsteiger and Carrick must be rested.Red or Blue? Its hard to tell if United capitalise on the absence of Aguero and if Fellaini plays, then they may just edge it.