Our squad has a chronic lack of wide players or attacking midfielders. Hopefully Allegri realizes this. We have Vidal, Pirlo, Pogba, Asamoah, Marchisio, Marrone and Pereyra. I guess we got Pereyra because why? Because he can also play as A CM!!!!
To be competitive in Europe its not about whether you play 433, 4231 or 4312 etc - sure its a factor but. In order to play any of those you need attacking midfield players. At this moment our hopes are pinned on Pereyra. That was a good deal (loan + option to buy) - an industrious player with potential. HOWEVER, we will never go far in the champions league with such players.
I do agree that if Vidal goes, we need to invest that money into creative, attacking players who can stretch defences and/or provide assists. Pirlo gives us creativity deep but we need more further up the field - that would only make Pirlo look even better.
I mean, if Vidal leaves, why don't we go for Jovetic AND Shaqiri for example. We need 2 of these types of players. Vidal would not need a direct replacement if he left as we are VERY well stacked in the CM department.