I voted Tevez, BUT......
I think that since our striking options improved with Dzeko coming in and Balo coming back, we now miss Silva more than we miss Tevez if either can't play. The Fulham game was crying out for Silva.
Tevez has carried us for about 15/16 months but I think we play more through Silva now. In an ideal world we'd have both on the pitch at all times, but you get what I mean.