Immobile bagged a hat-trick, while Insigne scored twice as a second-string Italy overcame Fluminense on Sunday - their final warm-up match before the FIFA World Cup in Brazil.
Italy and Fluminense offered up an entertaining match at the Estadio General Silvio Raulino de Oliveira, with Napoli's Insigne and Borussia Dortmund-bound Immobile on the scoresheet during the opening half.
"This evening we saw some interesting things," Prandelli told Rai Sport post-game after Italy ended their run of back-to-back draws against the Republic of Ireland and Luxembourg.
"Insigne and Immobile did well. We need to have more courage, but our condition is good."
"This is our final day of intense work. We will do some specific work this week and we will go into the match against England ready," Prandelli said.
"Balotelli? Goals need to be searched for, as Insigne and Immobile did," he said.
