Against Romania, it was obvious that the they were relying on Toni to score a header. Leaving Del Piero jobless, seriously how can Cassano, Del Piero Di Natale and even Quaggy do their job if all what Italy is doing is crossing to Toni.
And they say Del Piero and Di Natale didn't performe
Donadoni plays Toni because he has been doing so for the past two years and Toni has in fact always risen to the ocassion. The other reason is the 4-3-3, the idea is to have two quick players on the wings to be able to cross in the ball for the big man. Luca Toni is probably the best player in Italy when it comes to heading the ball into the back of the net.
The final reason is Luca Toni doesn't have a good enough replacement. Borri and Quaggy to play against France instead of one of the best finishers in Europe this season? A little hard to imagine although I personally have never been a fan of Donadoni's tactics. I honestly don't think there's a dire need for every squad to have a big hitman to head balls into the back of the net.
I'd rather see an attack made up of Cassano-Ale , Ale-Di Natale, or Cassano-Di Natale instead of just including Toni in all the time. I think this will work especially against France since they are ageing at the back and with two quick players like Cassano and Di Natale combining with a midfield of Camo, Pirlo, De Rossi, I think it could work wonders.
That's just my opinion as I prefer players like Cassano and Del piero a lot more than Toni and Vieri. However, realistically, Italy haven't demostrated too much creativity in this tournament and it seems resorting to high balls into the penalty area is their one and only solution. If they play this way aainst France, I'd be very surprised if they even come close to scoring.