Pirlo, who was one of the outstanding players at UEFA EURO 2012 and instrumental in getting Prandelli's side to the final that they lost 4-0 to defending champions Spain, is currently 33.
"Andrea has to decide for himself and in good time what he wants to do in the future and he still feels the desire to be a key player in the position," Prandelli told Raisport. "He wants to play to the World Cup and for us, he'll always be important."
Pirlo has scored ten times in his 91 appearances for Italy but has had a muted start to the domestic Serie A season with his league club Juventus.
Prandelli said that he was prepared to bring in a number of young players to the squad, such as 19-year-old AC Milan striker Stephan El Shaarawy or fellow forward Mattia Destro, 21, of Roma. Both won their first international caps after EURO 2012.
"We've got to renew and plot our future," added Prandelli. "We can't think about getting to such a tournament without making changes. The younger players need patience but the quality is there."