The Azzurri conceded three times in their final warm-up game before the tournament - Sunday’s 5-3 friendly victory against Brazilian club side Fluminense - and also succumbed to a late equaliser at home to Luxembourg last week.
"To correct certain faults, certain limits and certain mistakes, we need time," Prandelli told reporters. "The little time we have had we have used well.
"For 40 minutes yesterday we didn’t succumb to a single counter-attack. Of course, when you concede three goals you need to try to understand it, but if you make individual mistakes it is accepted and corrected.
"For the first goal, for example, we made an error in terms of continuing to play the ball even when things were tight. From now on, we mustn’t make any more errors of judgement."
The 56-year-old also took comfort from his side's strong attacking performance ahead of their first game of the World Cup, against England in Manaus, on June 14.
"We thought we would have an advantage by drawing their defence forward," said the coach. "After two minutes, they gave two poor offsides against us.
"Then in the second half, we brought the midfield line 20-30 metres further forward and we pressed them high up. As a coach I am very satisfied."