Kevin Pietersen is devastated as hernia ends his World Cup

England must get by without the injured Kevin Pietersen for the rest of their World Cup campaign, but are confident he will be back with a vengeance to prove himself again in 50-over cricket.

Pietersen yesterday described himself as "absolutely devastated" to have to leave the World Cup and be unavailable for the upcoming Indian Premier League too, because of a hernia which will require surgery. England coach Andy Flower is disappointed too, but consoled by Pietersen's assurances that he is committed to returning for England in all three formats.

Reports immediately before England set off for the World Cup last month claimed the mercurial batsman would be ready to forsake one-day international cricket at the end of the tournament, in order to concentrate on Tests and Twenty20s.

But Pietersen himself swiftly and unequivocally denied those plans, and Flower is delighted to take him at his word. "I anticipate him playing a lot of one-day cricket for England," he said. "He's 30 years old. He should be in the prime of his batting form, or coming up to it. He enjoys playing for England. He's an incredibly talented bloke, and we want to see him playing all three forms for England for as long as possible. I hope he's hungry enough to do that."

The strong indications from Pietersen to Flower are that he certainly is. "I don't see any reason why not," added Flower. "Last time I spoke to Kevin, he was very keen to carry on his ODI career with us. Let's look forward to that."

In the more immediate term, England have replaced Pietersen in their 15-man squad with the fit-again Eoin Morgan - a move ratified by the International Cricket Council this afternoon.

Pietersen's injury was diagnosed before their departure for the subcontinent, but medical advisers were confident he would be able to get through the tournament. It was revealed before their fourth Group B match against South Africa, though, that Pietersen would need an operation after the World Cup - in the hope of being recovered in time for the start of England's international schedule at the end of May against Sri Lanka and India.

But after bowling eight overs of off-spin, and making just two runs in his new opening role yesterday, Pietersen felt he was in too much pain to carry on. "He couldn't move properly," said Flower. "He's struggling to move at the required efficiency you need for international cricket, so we've taken the decision to send him home. He'll have the operation as soon as possible. We wish him well and we've replaced him with Eoin Morgan, who'll be arriving in Chittagong tomorrow afternoon."Pietersen's early departure means England face a hasty change of plan at the top of the order - with Ravi Bopara, Ian Bell and Matt Prior the three obvious candidates for promotion to bat alongside captain Andrew Strauss.

Flower and Strauss have three days to make that decision before they take on Bangladesh in Chittagong in their penultimate group fixture. Whoever moves up, though, it seems the coach is at ease with the notion of Morgan slipping straight back into the team if necessary. Out-of-form Paul Collingwood, who is also carrying a knee injury, was dropped in favour of Bopara for the victory against South Africa.

But Morgan - who had to be replaced, by Bopara, in England's initial squad because of a broken finger - is the man England surely want most to be coming in at number five. Flower said: "It's unfortunate for Kev. But we've got Eoin, who is a proven performer in this form of the game. We're glad to have him."