IPL boss Lalit Modi has raised the stakes over Kevin Pietersen and Andrew Flintoff's involvement.

England's two highest-profile cricketers are thought to be keen to take part in the second instalment of the franchise Twenty20 tournament. But the potential clash of dates between the IPL and the start of England's Test summer means there is uncertainty over how many matches they might be free for.

IPL chairman Modi said: "Are the franchise owners happy for Kevin Pietersen to play a handful of matches and then go away? I don't think anybody would be happy with that."

He continued in the December issue of the Wisden Cricketer: "He wouldn't add any value and would be more of a disruption. It takes time to gel with team-mates and to become part of team strategy and implement that strategy."

Modi fears Pietersen and Flintoff's contractual duties to England may well prove an insurmountable obstacle, next year at least.

"They need to be there for 15 or 16 matches -- substantial numbers of games," he said.

"If you ask, 'Is that practical?', I don't think it is currently."

Only an England and Wales Cricket Board agreement to alter the start of the domestic season could clear the way, according to Modi.

"The good thing is that we are moving closer to trying to resolve the issue," he reported.

"If we can't agree for the next year, I hope we can agree something for the next (International Cricket Council) Future Tours Programme, so we can move our tournament further forward and the ECB can move their season - so they sit further apart."