Shinji Kagawa's arrival has prompted many articles/debates on how Manchester United will play this season. Kagawa's position whether Ferguson intends to play him in the hole or on the left will have intense competition as United are already well stacked in those positions. Their best performances in the past decade in Europe came about when they played a 4-3-3/4-5-1 with a fluid front 3 in Rooney,Tevez and Ronaldo. And in tough away games,where Ferguson felt there was need of more graft and discipline,Park replaced one of the three. After Tevez and Ronaldo left,Ferguson opted to play on the counter with Rooney and Nani's pace and packed the midfield with Scholes,Fletcher,Carrick and Park.Although this strategy was a success(They beat Milan 7-2 over two legs),injury to Wayne Rooney during a key period meant United couldn't win any trophies. Although they reached the 2011 Champions League final playing Giggs and Carrick in the center,the only quality team they encountered was Chelsea and at that time the blues were in a mess with Ancelotti unsure about Torres's role in the team. With Kagawa's signing ,Ferguson needs a rethink in strategy to improve their chance of success in the Premier League Betting stakes.
Having not signed any central midfielders so far ,going back to the 07-09 days of a 4-3-3/4-5-1 makes sense. Playing with a front three who can switch positions with fluidity requires all the three players to be comfortable playing on the left,middle and on the right. And United at the moment have Rooney,Nani,Young,Welbeck and Kagawa who can or have the ability to do the same. Also both to get the best of Cleverley/Anderson it is better that they play in a midfield three. Both of them don't have the positional discipline to play in a midfield 2, and playing both Carrick and Scholes(If United don't buy anyone else) deep with someone ahead of them who offers a easy passing option makes sense.
Zonal Marking on United's 4-3-3(2007-2009)
The reasons Ferguson could afford such a loose shape in the final third were that (a) Ronaldo, Rooney and Tevez were all highly versatile, happy to play either on the wing or through the middle, (b) The three had a wonderful understanding in and around the penalty area, meaning Ferguson could effectively hand out three ‘free roles’ and sit back and witness the results and, crucially (c) All three understood their defensive responsibilities.If United were to play with a 4-3-3 now,probably the front three would be Rooney,Kagawa and Nani. Playing Welbeck instead of Kagawa and pushing Kagawa into midfield also would be an option. All of them have a good understanding in and around the penalty box although lot of work has to be put on the training ground if they have to combine well with each other. And as far as defensive responsibilities go,leaving Nani all the others are pretty good at that too.
When Ronaldo was at Old Trafford,Rooney had no qualms about playing on the left when asked to. When defending,he generally took up the left side of a midfield five and carried on with his job unselfishly. Even now among all the best attacking players in the world, Rooney may be the most hardworking and unselfish one. But in two of his biggest games over the past two years he has let his team down. Against Barcelona in the 2011 Champions League final,he let Busquets initiate Barcelona's moves and also didn't do much to stop Pirlo in the Euro 2012 quarterfinal against Italy. Him being the best player and the best chance of scoring for both Manchester United and England may be one of the reasons. But playing with a midfield three rather than asking Rooney to play as the third midfielder will free him up.
If Ferguson opts for a 4-3-3(With a fluid front 3),two players who wont see much game time will be Valencia and Hernandez. Valencia arguably United's best player last season is more suited to playing on the right without switching flanks or moving inside. And Hernandez has to add lot to his overall game to be a regular starter. But for United to do well in Europe,Ferguson needs a rethink in strategy,playing with two central midfielders might have worked for him in 2010-11, but it probably isn't going to work again.