"Cagliari were set out really well and put pressure on us. We didn't do as well with the trident attack as we had done midweek at PSV Eindhoven," said Mancini, who saw Julio Cruz and David Suazo hit Inter's goals.
"The team was too static in the first half. Cristian Chivu is a great player who, like Nicolas Burdisso and Javier Zanetti, can take on a number of different roles. With so few midfielders at my disposal right now, he represents a good alternative."
There is an injury crisis within the side ahead of their showdown next Sunday afternoon - the Milan derby.
"I doubt we'll get any of them back by next week, but the real problem is Dejan Stankovic. If the tests don't go to plan, he'll need surgery and could be out for two months."