How can a player signed to play alongside someone, also be his replacement when he gets injured? Unless we're cloning him to have two of them upfront?
It's fairly clear, looking at the strikers we have at the club, that Balotelli and Sturrdige were signed to play upfront together.
He wasn't just signed to play alongside him.
There was a plan for when Sturridge is fit and available, and a plan for when he is not. In addition to a plan for the different systems that Brendan prefers.
As soon as he got injured we moved back to one up front, with Balotelli stepping in for Sturridge in that role. We didn't bring in another striker and play two up front regularly, did we? Which we could of done.
So yes, Balotelli was signed to play with him in the midfield diamond, two up front formation, and in place of him in the 4-2-3-1/4-3-3.
And the original poster you replied to is right, we need somebody who can do both, and Mario does not look like that man at the moment.