Weakness
In order to use this formation, you've got to have a talented squad. The centre-backs, in particular, need to be of a specific mould.
The outside two must be mobile and have good agility. You only have to look at how Eden Hazard turned Ivan Ramis in
Chelsea's opening game against Wigan to see what can happen.
The central defender must be dominant in the air and happy to move forward with the ball—if he isn't positionally perfect, none of them are. It's flawless, or it's tragic.
When three at the back meet one up front, it can become tough to figure out who should mark the front man. If the central player man-marks, what do the others do? Little things can throw a three-man defence when it's inexperienced, as
City found out at Anfield in the Premier League.
The biggest worry for a 3-5-2 is when one of the defenders is dragged infield, or gets lost. The success of a back three lies in its rigidity, so when the line is destroyed, the outside two will squeeze in to try and compensate.
This leaves massive holes, as there are no full-backs whatsoever. This is where the danger of the false-nine lurks, and why it proves Daniele De Rossi is a world-class thinking footballer as he refused to fall for Cesc Fabregas' traps in the Euros.
Conclusion
Do it right and the 3-5-2 is brilliant, do it wrong and it's self-destructive.
It's flexible, accessible and refreshingly different, allowing modern day full-backs to unleash their attacking potential and reduce the strain on their defensive duties.
For centre-backs, it ushers in a new dawn of clever players. If the 3-5-2 were to become mainstream, limited defenders who simply tackle and clear would be in danger of becoming redundant.