I we are going to sign a player, be it in january or during the summer, winger and GK are the only 2 positions we could arguably need more depth. We got a great set of striker in Rooney, Berba and Owen, with Macheda and Welbeck itching for opportunities.
The CM position is very deep, I mean SAF must have nightmares figuring how to give consistent playing time to Ando, Scholes, Giggs, Fletch, Carrick and Hargo, and we also got youngsters like Possebon, Cleverly, Akrem, Gibson and Ljajic (who looks very promising as a creative mid).
We are set at fullback, Evra is arguably the best LB in the world, Neville, Oshea, Brown are solid and the twins Rafael and Fabio look as promising as any other 18 year old fullback out there.
At CB we got one of the best pair in the wolrd with Vidic and Rio (It's a pity his injuries have affected his form this season) Evans is playing very well and Oshea and Brown are very solid also.
So GK and Wingers are where we have a little bit of trouble. Van der sar might retire after this season or the next, Foster and Kuschack (spelling) have look good but they have been very inconsistent, so we could go after a GK like Akinfeev, or wait untill Foster or Kuschack become more consistent.
On the Wings, Valencia has been playing very well, Park is very consistent and a very good all around player, but he doesnt pose a threat to opponents, Nani got all the talent in the world, but he hasn't been to play to his potential, he is still very younf thou, and then we've got Obertan and Tosic, both look like very good players, Obertan is very talented, he's played well in his few games and he looks like he could go on to become one of the best players in the world, as for Tosic, he is also very talented but his only problem seems to be he is not strong enough for league. So maybe signing Silva or Di Maria would be a great piece of bussines for us.