Other captains have had their fair share of sleepless nights but following Kevin Pietersen's sudden exit, England skipper Andrew Strauss can be forgiven for wondering what he has done to be denied a moment of tranquility.

Sunday's thrilling six-run victory over South Africa had barely sunk in when news filtered in that Pietersen would return home immediately, and not after the World Cup as earlier thought, for a hernia treatment.

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His scores of 39, 31, 59 and 2 may suggest that the towering right-hander, squirming in the makeshift opener's role, had not set the tournament alight.

But his absence does throw England's World Cup strategy into disarray, forcing a mid-tournament shake-up which may well do no good to a team chasing its maiden ODI World Cup.

Instead of analysing the strength and weaknesses of their remaining Group B opponents Bangladesh (Friday) and West Indies (March 17), the English management are instead taxing their brains trying to get the batting order right.

To fill the void, they are flying in Irish-born Eoin Morgan who possesses no less flair -- certainly in this form of the game -- than the man he replaces.

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The 24-year-old Dublin-born Morgan was left out of the squad because of a broken finger but it healed fast enough to invite an unforeseen call-up on Monday.

Going into the World Cup, England experimented with the line-up that struggled in the ODI series in Australia, losing 6-1 having retained the Ashes comfortably.

Pietersen was unveiled as an opener at the cost of Matt Prior, who the team believe, would be more at ease in the middle overs because of his ability to handle spinners better than some of his teammates.

Pietersen's absence might tempt the team to ask Prior to accompany Strauss at the top, especially with so many teams here opening with spin, while they also could thrust the makeshift opener's role on Ravi Bopara after he shone against South Africa.

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Strauss also does not believe that the team's bowling woes in the World Cup have vanished overnight despite Sunday's thrilling victory.

After bleeding runs heavily against the Netherlands (292), India (338) and Ireland (329), the same English attack defended a 171-run target with aplomb.

To a large extent, they owe their sudden improvement to a surprisingly benign track at the MA Chidambaram Stadium and Strauss clearly does not want his bowlers to develop an inflated ego.

"History suggests you don't often play on pitches like that, no doubt about it ... It probably broke up too much for a one-day game."

No wonder Graeme Swann turned the ball square and pacemen James Anderson and Stuart Broad generated swing -- both conventional and reverse -- to torment the South African batsmen.

South Africa captain Graeme Smith also felt the "inconsistent surface" aided the English bowlers in the low-scoring thriller.

"I think there was a lot on offer for the bowlers -- reverse swing, spin, inconsistent bounce. It was a bowlers' day even though in one-day cricket it's mostly the batters' day. It's difficult to complain but it was not easy to bat on."

Strauss cannot really relax also because if there was tangible improvement in the bowling and fielding departments, suddenly cracks have started appearing all over their batting order, which had hitherto been their saving grace in the tournament.

England lost three wickets, including the scoreless Strauss, for 15 runs inside five overs and could not really recover from the dreadful start against South Africa.

The only silver line was Jonathan Trott's consistency in the tournament and Bopara's sense of occasion, making the most of his inclusion in the first XI, thanks to Paul Collingwood's dodgy knee.