MANGARATIBA, Brazil -- Italy faces England in five days at the World Cup and all of a sudden Mario Balotelli is no longer a sure starter for the Azzurri.

Ciro Immobile and Lorenzo Insigne combined for all five goals when Italy beat Brazilian club Fluminense in a World Cup warm-up match Sunday, whereas Balotelli hasn't scored for the national team since October.

"Clearly we have some healthy competition up front," coach Cesare Prandelli said Monday. "Everyone has a chance. Whoever doesn't play will have to accept the choices. ... Potentially there could be a lot of stars in this squad."

Two years ago, Balotelli's goals helped Italy reach the final of the European Championship. But the temperamental forward is coming off an inconsistent season with AC Milan, while Immobile led Serie A with 22 goals for Torino then signed with German power Borussia Dortmund a few days before flying to Brazil.

"Goals are always important, even when you score them in training," Immobile said. "I'm working as hard as I can and if I get the chance I'll be ready. The coach makes the decisions and we just need to make our contributions -- whether that's from the bench or from the start we need to give our all."

One thing that appears for sure is that Balotelli and Immobile will not play together.

"Anything is possible but having two centre forwards with so many quality midfielders would be forcing things a bit," Prandelli said. "Anyhow, I'm going to choose on the basis of how we want to face the (opponent) and how the players are physically and psychologically."

The England game will be played amid thick humidity in the jungle city of Manaus, so physical fitness will be a key factor.

At Euro 2012, Antonio Cassano paired with Balotelli in attack but rarely played more than an hour. Cassano was coming off minor heart surgery then and even though he's 31 he appears in better form now.

Prandelli has constantly talked about changing his tactics as matches wear on, and it could be that he's preparing two distinct options in attack -- either Balotelli and Cassano or Immobile flanked by Insigne on the left and Alessio Cerci on the right.

Immobile and Insigne won the Serie B title together with Pescara two years ago on a squad that also featured new Italy midfielder Marco Verratti.

"We played together for a year and we know each other well," said Insigne, who was a controversial Azzurri selection ahead of Giuseppe Rossi. "The movements are still the same. ... I would accept any position and give my all, even in goal."

Insigne finished the Italian season in solid form, scoring two goals when Napoli beat Fiorentina in the Italian Cup final last month.

Whatever he decides, Prandelli believes that Italy has done enough physical preparation, even with Costa Rica and Uruguay also awaiting in a difficult Group D.

"This squad has the legs and enough gas in the tank to reach the World Cup final," the coach said. "Everyone knows their job and everyone should understand that at a World Cup you can be a protagonist even for just five minutes."