Giles Clarke admits England players who do not renew their central contracts would be free to play in the Indian Premier League - but they could also jeopardise their international futures.

England's star names - such as Hampshire's Kevin Pietersen - will not feature in the IPL later this month as it clashes with the Test series against New Zealand.

And Clarke does not expect coach Peter Moores to release players for the 2009 tournament when there is a gap in the calendar.

Rose Bowl star Pietersen recently indicated that England players would want to eventually feature, and an option is not being on a central contract yet still be available for international selection.

Clarke, chairman of the England and Wales Cricket Board, said: "It would free him up in that sense. It's a risk he would take.

"KP runs the risk, as anyone does, of losing his place or ending up getting injured.

"Employment contracts are a matter between the employer and the employee - they are not compulsory. If you don't want to be employed by somebody you don't have to.

"Then you run the risks of not being employed by that person. That is a risk you may choose to run. Cricket careers can come to an end as well as begin."

As it stands, the IPL will not use players if there is a clash with international cricket, but next year's tournament will be between England's tour of West Indies and the Ashes series.

Clarke highlighted the need to maximise the chances of defeating Australia next summer.

"I couldn't see anyone centrally contracted playing," said Clarke. "I can't see Peter Moores determining that he wishes to release him.

"The risks are very significant. We're about to play Australia. If Peter Moores released a player and he got injured, what would the reaction be?

"Spectators want to know that our players are as fit and sharp and ready for the Ashes series as we can ensure they are."

Clarke is aware of the financial rewards but argued that England players have contracts to honour - and losing their place in the team would offer others an opportunity.

"I understand the point that a career has a certain limit, we're not stupid," he said. "But the England team is the critical part of the economics of our game and the best players being in the team is a critical part of the economics of our game.

"Tony Greig felt it was appropriate to play in World Series Cricket - and Ian Botham appeared out of pretty much nowhere.

"There are risks and rewards here. We have a clear understanding with IPL that Future Tours Programme takes place anyway."

Clarke insisted England's Twenty20 domestic tournament is not a rival to the IPL, which is in the same format.

But he added: "We're more than prepared to ensure our Twenty20 remains the most exciting domestic competition played in the world at that time.

"We want to see what we can put together that is economically sensible and at a time when spectators would like to watch and use it as a stepping stone to watch an ODI or Test."

Hampshire skipper Dimi Mascarenhas is the only English international playing in the IPL this year, but not for the full campaign which runs from next week until late May.