This one man is the perfect example for showing fickleness in football. Personally, I'd drop him now because we all know he's going to get slaughtered on this forum after the next game.
On a serious note, Porto are a very competent possession based team who DIDN'T overrun our two man midfield. I genuinely think a lot of this formation talk is pointless. I think it's the individual player instructions that make the real difference. A two-man midfield, minus Okazaki at CAM leaves us very light and yet that didn't seem to matter at all. As soon as you put an extra man in midfield, you're leaving a striker without a partner or, even worse, taking away the energy and width from the wingers.