Duncan Fletcher fears KP's emergency elevation to the England captaincy may have a detrimental effect on his mercurial batting.

The former England coach is worried the extra onus of leading the side - Pietersen was called into the role because of Paul Collingwood's four-match ban for overseeing a slow over rate - could compromise the middle-order batsman's innovative style.

"I'm not sure if Kevin Pietersen should be captain at this stage of his career," Fletcher explained in his column in the Guardian.

"He's a free spirit - just look at that superb switch-hit at Chester-le-Street - and I'm worried the added pressures of leadership will affect the way he bats.

"For me, Andrew Strauss should have been picked and should have been captain."

Fletcher returned to familiar themes as he put the blame for England's NatWest eclipse on the failings of county cricket.

The Zimbabwean was noted during his up-and-down tenure for a policy of allowing his players little if any opportunity to take part in domestic cricket.

Instead, he prescribed rest and practice time between Test and one-day international exertions - a formula largely abandoned by his successor Peter Moores.

"The bowlers should be blamed for what happened, but the problem goes deeper than a few wayward deliveries," he said, in the light of the 51-run reverse at Lord's - which wrapped up a 3-1 series scoreline in favour of the Kiwis.

"I'll say it until I'm blue in the face: it all goes back to county level," adds Fletcher. "How much has county cricket really taught these guys? How much are they practising in the nets? The answer is not a lot, because there is simply no time to have nets."