Italy were stunned by Haiti in their warm-up game ahead of the Confederations Cup.
"There's no need to worry. Something didn't work and we need to be more careful, but I'm sure we can work on those issues in training," the Napoli man told Rai Sport.
"We have a very reliable and professional squad, so there are another four days in which we can find our best fitness levels for the Confederations Cup.
"At Coverciano we did specific fitness work and much of it in the gym. With that and the long journey, as we arrived yesterday, we weren't at our best.
"I remain convinced we will be ready for the start of the Confederations Cup. On paper Haiti are far inferior, so this result has to make us reflect on the situation. At the same time, it's important to stay calm."