No doubt in my mind that Big Phil needs to find a way to get both Drogba and Anelka on the pitch at the same time for the full 90 minutes.
Whether that means going to a 4-4-2 or using one of them as an attacking midfielder i don't know. but you only have to look as far as last seasons Champions League semifinal when the pair hooked up for a wonderful strike just before the whistle of the first extra time period.
These are 2 world class players that can create havoc for any back 4.