There are a lot of strikers out there where you say "he wasn't in the game and then he popped up and scored two". That's sort of the point. Jozy has done this a few times for us and I think it is a good thing. Let opponents will focus on Giovinco, who can beat them off the dribble then find the forgotten man.
I mean, hell, Pippo Inzaghi made a whole brilliant career out of disappearing from games until just the right moment.