You mean about the wings? Amauri could partially cover that role, reverting into a 4-4-2 as we defend and with a little help from DC from the other side! Having them on the wings and Marchisio closing in from the center, we would create a multidimensional front that would force them to pull back and defend with two lines.
If they fall back, our fullbacks will be free to approach and provide an advanced support. Having 3 forwards +3 MDs + DC crosses and runs we could still overwhelm them. Then, our superior technical skills would take over and our champions will do the difference. One mistake from their side and they are undone. Both DP and Amauri are particularly effective in this type of conditions, as they tend to return back and play as wingers, if there is a lack of creativity and support. But this time, they wont have to assist the man on the other part of the field, the CF will be there to provide a constant threat and keep the CBs in the center! If DP or Amauri go past through a Cagliari fullback,
which is a very possible outcome since they are normally unstoppable at 1 o 1 situations, its going to be them and Trezequet against the CB who is guarding that sector

I expect to see at least 3 goals under those circumstances.
I honestly dont see Grygera and Marchionni being more effective offensively than Amauri and Mellberg from the left. And the same stands for the other part with Molinaro+Neddy vs DC+DP.
But there certainly is a defensive risk over there, Sissoko and Chiellini would have to fill the gaps of DC's advance and not let anyone slipping through and CZ swift passes may provide what Mellberg may not be able to provide from the other side. Thats why why Marchisio has to be there instead of an AMF (Giovinco, Tiago), to provide coverage as/when needed. And i hope with the addition of Chiellini, our weak defense will not shatter against the Cagliari forwards.
We cannot afford that against superior teams. This is our greatest flaw as a team!
But its Cagliari we are talking about, if we cant try the trident on them, i wonder when we can...
There will be times, when this trident/scheme will be used, so we better start using to test its efficiency. We wont have the time to fine tune it against Chelsea, if needed (after we concede two goals) for example. A small mistake in our tactical approach would be lethal there, the class of our opponents would sense and exploit it.