Well, I think in the next two (winter+summer) windows we need a small shakeup in the squad. At the moment we are 1 player short: i.e. a striker short if we want to play 442 and a winger short of we want to play 4231. I'd prefer to build the team around Silva so I would prefer 4231 and I would like to see the following in:
1) Pogba or Koke or both
2) Schneiderlin or Barkley if Yaya leaves AND we get only one of Pogba or Koke
3) Reus
4) Isco if Nasri or Jovetic leave
5) Ricardo Rodriguez for Clichy or Kolarov (I would want to move Clichy on, but the HG rule might prevent that)
6) Experienced center back if Demicheles leaves. Chiellini or Pepe
We are looking at a net spend of at least 80-100 million in these 2 windows, probably more. But its much needed to being in youth and energy in the side while simultaneously raising the level and potential level of the squad. We would also need to be careful about the HG quota. At the moment we could get 1 non HG in, but thats b/c of the squad limit. For me, that place is reserved for Reus. I'd really have preferred to get Pogba in Jan (and its a possibility Juve may be out of the CL in the group stages again) so that IF he isn't HG yet and requires a few months we make sure he gets the HG qualification by being with us. If we get him in summer, I don't think he would get HG qualified. But with his new contract it might make this really difficult (or really difficult and really expensive).
I've said Koke or Pogba or both as my 1st choice b/c replacing Yaya won't be easy. His ball control, box to box ability and finishing aside its his passing and control of the game that we will miss the most. With a combination of Pogba and Koke we would have control b/c both players are very good technically and I would rate Koke's controlling skills as higher than Pogba at the moment. Both are hard working and Pogba is as close a physical replacement for Yaya as we could get. Those two together would be supreme. Get those 2 and we can say good bye to Yaya easily.
If we do get only one from the 2, then I could see either Yaya staying for another season, or us needing another CM. For me then that should be a HG one and I'd prefer Schneiderlin or Barkley. Schneiderlin is a proper holding midfielder, he can play in a 2, and has better ability on the ball than Fernando. Barkley is more attacking than I'd prefer in a CM; he would need to develop tactically and defensively a lot. Short to medium term Schneiderlin is the better option, long term Barkley might become a better offensive CM but at the moment I cannot really see him play in a 2 man midfield
Reus is obvious. We need width: not just width, put a pacy dribbler who scores goals. He can replace Nasri or Jovetic or slide in without any attacking/wide midfielder needing to be moved on (as we are 1 man short). But it would cut into the playing time of one of those 2 a lot.
But if for some reason we do need to move Jovetic (part of Pogba deal) or Nasri (wages) on, we should get Isco. He'd slot straight into the 1st team.
Our left back situation is dire. Kolarov is very good going forward and to me at least he is defensively good (at least doesn't make mistakes) but Clichy offers nothing going forward and makes mistakes. Although checking the PL stats for last season Clichy was ahead in tackles and interceptions per 90 mins, I think its a case of stats misrepresenting the situtaion. We have 2 options, either go for the defensively sound Left back, or get an attacking left back who has pace to recover and intercept (one of Kolarov's weakness, am pretty sure if he had more pace he would be much better at defending). For me, I do not think we need to look any further than Rodriguez, he is almost as good going forward as Kolarov but isn't limited by his pace. He is also decently tall (6 foot) so that should the back line too)
Other than that, if Demicheles leaves we need an experienced centerback who can slot right in with either Kompany or Mangala. Chillini on a free is a no brainer, although wouldnt mind Pepe for decent money though
That's about it. I think we can dramatically improve the squad and the team. Even if the individuals we bring in might not be as illustrious (for e.g. Yaya's replacement), I think the effect on the players as a team would positive. E.g. I think Koke and Pogba in midfield or one of the two with Fernandinho, with Silva @ 10 and Reus and Jovetic/Isco/Nasri as wingers would allow us to really play the pressing game the Txiki/Pellers wants us to.