Three at the back is perfectly fine theoretically but we don't have the squad currenty to play it two times out of three in a single week. However, it should be noticed that our fixture list has been a bit anomalous in that we've played two of the hardest games we'll play all yelar in very quick succession, with a trip to Croatia of all places to spice things up over a monstrous six day period.
Three at the back also doesn't work when there's only one real forward with everyone else running from deep, as both Willian and Fabregas did to immense effect today. Three at the back will work far better against United who play further up the pitch, and dare I say it, I think it will work well to nullify the kopites if we go one up at their place. Big if that like, and I'm looking forward to the inevitable vaulting