Last Nights Formation

I have only seen highlights from last night's game but it seemed the formation was more 3-4-1-2. Judging by the highlights Mata looked to be playing a lot more central then out wide.

I have read it was a 3-4-3 so have I missed something??. Also now we know Van Gaal is going with 3 at the back that will surely mean at least 2 CB's in with hopefully another CM?.