He's focused his formation on drogba. But not the team itself. Since we having set backs at left back, and malouda is covering it, Angelotti needs to use Ivanonic and malouda as wing backs. With Mikel holding infront of terry and Carvalho. This doesn't ruin chelsea at all, it's a tactical decision that needs to happen at this stage. And the rest you can pretty much figure out, even though ballack is now suspended. ( J.cole can move into the central midfield along side Lampard, Something that people don't consider putting j.cole. He can play in the center/midfield three and spray the ball about. And knowing angelotti, it'll be Drogba up front with Anelka on the right.
But, i'm just stating my opinion on who should be playing.