I think Mikel, Essien, Drogba and Carvalho have been amazing this season. SWP and Cech have also been gd but late on in the season.
I think that we need a CB (most likely in the form of Alex), a RB and a striker. Especially as we will lose both Kalou and Drogba to the African cup of nations, and Sheva on his own isn't the best replacement.
Also next season I would like to have Robben fit for a whole season no injuries. Doubt it tho
