Liking or disliking Molinaro, it is obvious that he, and the other fullbacks we have, are not only our weakest link, but they also don't have the characteristics the fullbacks need to have for 4-3-1-2.
Molinaro has the stamina, but is nothing more than an ok defender and awful attacker. De Ceglie lacks a lot in defending and isn't someone who can run up and down all the time. Zebina is too injury prone to last throughout the season, Salihamidzic is only average both in defending and attacking, Grygera isn't capable to cover the whole side and he'll usually sit back without providing anything on his side in opponent's part of the field, while Caceres....well, i can't really judge him for now. From that single match he played so far he showed nothing more than awful decision making and positioning.
We can live with one of these guys on one side if we had a great fullback on the other side, but this way i'm really sceptical.