City's need it seems to me, are at Centerback, and Out wide. I consider Nasri, SIlva, and Milner as our in-between players. who bring continuity, creativity and drive to the City offense in midfield. The City defensive part of midfield can be well managed by Barry, Nigel and Hargreaves (In the absence of Yaya). AJ and Balo are our wild cards, and Aguero/Dzeko our strikers.
Knowing the above, City's has 2 areas where improvement via acquisition can be made. At CD, we can improve ball distribution and movement from that area (Savic is capable, but his defending is not up to par yet, and Rekik is a bit young even though he looks like a stud). The second area of need is offensive speed. We don't have a player with lightout speed of the Lenon, Bale, or the kid at Arsenal variety. Which will be a good option to have on the bench. Thus,I would look to find a speedy wide player.
That need for a speedy wide player is really In case we suffer injury to either Clichy or Richards and need to have an attacking player with speed to make up for what they normally bring or if they are rested. These too are the keys to our wide play. And as good as Kola/Zab are, they don't bring the same offensive cohesion or threat that these two possess.
Thus, if I were the Brain thrust for the January transfer, I'd look to transferring Kolo to PSG, Tevez to someone. Kolo because he wants to start, and his abilities are dwindling, but we can get good money for him if the PSG rumors are true. And thus I will not hesitate to make that trade. In his replacement, I'll bring in who we should have gotten in the summer to start with- Vertonghen. He is available, will be around in January, and can improve the need for a great passer from the CD position, as well as play DM. LB or LM if injuries occur.
Which leaves us with only one other area of improvement from the outside. Speed! We have it at fullback, and when both are on the pitch, we probably don't need it anywhere else. Butin the even that one or both are either not available or are being rested, we need a player (not a fullback, but preferably I wide player) who can replicate that edge in front of Zab or Kolarov. My preference or best option out there is probably Lavezzi (as he is also versatile) but Lavezzi is not an option since he is still in the Champs league (one of the misfortunes of not making the 2nd round). Hoilett may be an option, or we could look to the second tier or Eastern Europe to find a player. The key here is that we are not looking for a pre made star. Just someone with certain qualities that we presently lack.
In essense, if we can't find that player, I will just stop at bringing in Vertoghen, selling Toure and Tevez. And continue to work on getting loanies off the books.