With Manchester United having signed Shinji Kagawa from Borussia Dortmund, question marks surround how Sir Alex Ferguson will fit the new Japanese ace in to his team.

The Red Devils utilise a footballing system that doesn't suit the £17 million man's strengths, so to get the best out of him, Ferguson will have to change formation.

Throughout the 2011/2012 season, it was clear that the Manchester United boss wanted to switch to a more possession-orientated setup but lacked the peripherals to do it.

In the intermediary, Wayne Rooney and Danny Welbeck were used in a 4-4-1-1, so Rooney could drop in and out of the front line in a dangerous and unpredictable role.

The 4-2-3-1 is a fashionable, effective formation. It is utilised by many of the better domestic and international teams such as Manchester City, Bayern Munich and Germany.

With Kagawa officially in town, Ferguson needs to migrate to this. This shouldn't be too much of an issue, as according to Jonathan Wilson in Inverting the Pyramid, the Manchester United boss has excelled in keeping his teams current and contemporary—something which sets him apart as an elite manager.

How Kagawa and Rooney can run United's 4-2-3-1 offense

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With Borussia Dortmund, Kagawa lined up as the central attacking playmaker in a 4-2-3-1. At times he adopted a right or left wing position as Jurgen Klopp's mysterious yet effective methods of shifting the playmaking role forced him to do so.

He slotted in between the defensive lines with real success, making him impossible to track, difficult to shut down and, infuriatingly for the opposition, wide open to receive a pass.

He would likely line up in a similar role for Manchester United behind Wayne Rooney, but don't be surprised if Rooney drops deep and Kagawa thrusts forward.

Back in Japan, Kagawa sometimes played as a striker and bagged over 50 goals for Cerezo Osaka before moving to the Bundesliga.

His finish is calm and his runs threatening, so him interchanging with Rooney is a sight I'd like to see and could well grow accustomed to seeing.

What will he contribute to the defence?

Don't be fooled—he is not a strong tackler, man-marker or header of the ball. What he does do is work hard, which means he won't shirk his defensive responsibilities.

At Dortmund he simply wasn't asked to contribute defensively due to the steadiness of Lars Bender, Ilkay Gundogan and Sebastian Kehl.

That doesn't mean he can't do it, though, as he is adept at slotting into a would-be-midfield five when out of possession.

What this means for the other squad members

Switching to a 4-2-3-1 will help unlock the best in some players.

It will utilise Kagawa properly while allowing Michael Carrick and Paul Scholes to share a deep, conservative midfield partnership—something which could look borderline unbreakable at times.

It will also develop a security blanket for Rafael's marauding runs and slight defensive issues. His runs are positive, but he does get caught out of position. A holding midfielder each side would block the channels and cut out the counterattacks created on the back of this.

Unfortunately, this would in all likelihood signal the end of Ryan Giggs' glittering career in the English Premier League. He doesn't have the legs to play as a true left winger or as a holding midfielder. Twenty-minute cameos are all you can expect from him in this formation.

Javier Hernandez, too, would suffer. Due to the lone striking role available, his playing time would likely be around the same level as the disappointing season just gone.

Conclusion

Ferguson now has the personnel to create a masterful, controlling team in a contemporary formation and style. This is a team that could snatch the title back off Manchester City, and it's arguable that just one more central midfield recruit is needed to complete the set.

This team was found out last season at times and were simply overrun by their archrivals in that do-or-die Manchester derby toward the back end of the campaign.

Kagawa is a wonderful signing, but he has to be used properly. It's also arguable that he fits straight into the loose 4-4-1-1 United used at times this season, but why not make the switch now that you've got the perfect player to make it work?

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