Italy coach Cesare Prandelli hit out at the World Cup organisers after seeing his side overcome England 2-1 amid stifling, humid conditions in Manaus in their opening game.

The temperature at kick-off in the Amazon rainforest city was 28 degrees Celsius (82 degrees Fahrenheit), with humidity in excess of 60 percent, but because the temperature did not rise about 32 degrees Celsius, referee Bjorn Kuipers was unable to call for any breaks.

While the game was initially played at a high tempo, both sides appeared to struggle physically towards the end, with several England players cramping up, and Prandelli felt that it was an unacceptable state of affairs.

"It's truly absurd we cannot consider a time-out," he told a press conference at the Amazonia Arena after Saturday's game.

"Luckily the referee intervened every now and again, but it's absurd. If we want entertainment, we need to enable the players to give great performances."

For all his anger over the conditions, Pellegrini was able to reflect on a strong performance that left Italy well placed to progress from Group D ahead of their second game against Costa Rica in Recife.

England striker Daniel Sturridge was quick to cancel out Claudio Marchisio's 32nd-minute opener for Italy, but a close-range header by Mario Balotelli early in the second half restored the Azzurri's lead.

Despite having a relatively quiet game in a lone striking role, Balotelli was named the official man of the match, but Prandelli said that he was not fully satisfied with the AC Milan frontman.

"I think he could do a lot more," said the former Fiorentina coach.

"I told him right before coming out on stage (for the press conference) that he could do a lot more.

"His potential is enormous. He just has to be persuaded that a striker's job is to finalise actions and passes.

"He has to continue to perform as he did this evening (Saturday) and keep giving his all, but I'm sure he has margin for improvement."

Prandelli praised second-choice goalkeeper Salvatore Sirigu, who came into the team for the injured Gianluigi Buffon and made important saves from Jordan Henderson, Sturridge, Ross Barkley and Leighton Baines.

Buffon, the Italy captain, sprained his ankle in an eve-of-match training session, but Prandelli suggested that the 36-year-old Juventus custodian could return in time to face the Costa Ricans on Friday.

"He got hurt yesterday (Friday)," Prandelli said.

"We tried for him to get better this morning, but we didn't have time. I think within a few days he'll be available. I can't quantify the number of days. He had a sprain, so I don't know."

Costa Rica pulled off the biggest upset of the tournament so far by stunning Uruguay 3-1 in Fortaleza earlier on Saturday and Prandelli vowed that Italy would not underestimate Jorge Luis Pinto's side.

"If we don't win the next match, we won't get very far," he said.

"Winning the first match can help from a psychological perspective, but the second will be crucial to get into the second stage.

"Before the tournament, everyone forgot to mention Costa Rica, but we know Costa Rica. We know it's a team that can hold its own."