I am 110% sure we will sign a CB, either Alex or Lugano, most likely Alex. Marotta knows we need one. Same with LW, although I won't be completely convinced if we buy Giaccherini. Vargas/Perotti/Bastos would satisfy me, but who's to say that Giaccherini won't turn out like Matri for us? He wouldn't be a great signing but not a terrible one either.
I think you are missing the point with midfield. We have only spent €10.5M for the Pirlo-Vidal midfield. If we kept Melo and played Marchisio-Melo, we could have €25m for a LW. Mata is going to Chelsea for €30m...The improvement in midfield far outweighs the improvement if we bought a LW who is worth €10m more. The best winger under €25m that we could buy is probably either Bastos, Marin or Carlos Eduardo. None of them are a massive improvement over say Vargas or Perotti and are in the same price range. Without sacrificing other postions the most we can spend on a winger is about €15m. Then next year if we make CL we can buy a WC winger worth €30m+ such as Ribery, Hazard, Mata, Di Maria, Hulk, Nani etc.
I would prefer to have Vidal-Pirlo and say Vargas or Bastos on the left wing than Melo-Marchisio and Mata on the left wing. The first is far more balanced and a lot less risky than having an unstable Melo and ghost Marchisio in the middle. In that system, the wingers would have to come up very deep to get the ball since neither Melo or Marchisio have great passing ability like Pirlo.
SS, well I already said why that's necessary because of injuries. If we didn't buy Vucinic, our foward line would be the only position where we would have 2 players capable of starting.
GK: Gigi, Storari, Manninger
RB: Licht, Sorensen, Grygera, Motta,
CB: Chiellini, Bonucci, Barzagli, Sorensen, + new CB (Alex)
LB: Ziegler, De Ceglie, Grosso, Chiellini, Grygera
RM: Krasic, Pepe, Pasquato, Martinez
CM: Pirlo, Vidal, Marchisio, Pazienza
LM: Pepe, Pasquato, Martinez, Marchisio + new signing.
Foward line: Matri & Quagliarella
Del Piero can't be expected to play 90mins anymore, Amauri is leaving and Iaquinta as I said is made of glass and cannot be relied upon for usually more than 4-5 games at the very maximum without getting injured. Toni is 34 and is really not someone to be relied for whole games either. Out of that squad, I doubt many will leave, most likely either Manninger or Storari and Grosso besides the fowards.
Marotta is trying to build the base for a very good squad. By the end of next season, all the deadwood will be out (Iaquinta, Amauri, Grygera, Grosso and maybe Bonucci, Motta, Martinez, Barzagli & Pepe) and we will have a very strong squad which we can add WC players to. It IS the most logical way to go about things with our budget. We can't afford to buy WC players for every position.
I hope you see the light at the end of the tunnel now. But maybe it's just a freight train coming your way. (I don't know if this sounds stupid I just got home from a party and I'm drunk).