The competition, which offers a back-door route into the Uefa Cup, will take place from 24 June to 23 July and will severely curtail the summer recess for those clubs. Wimbledon have said they want to use players on loan to take part.
Mike Lee, the Premier League spokesman, said: "All three clubs have made it clear they are entering the competition in a positive frame of mind. They have come forward voluntarily."
Sam Hammam, the Wimbledon chairman said: "It seemed that English clubs might even have been banned from next season's major European competitions, so someone had to do it."
Ron Noades, the Crystal Palace chairman, has blocked transfer demands by four players. He told them: "We'll decide whether you can go when our new management structure is in place."
Gareth Southgate and the central defenders Chris Coleman and Richard Shaw have all submitted written transfer requests following relegation and the sacking of manager Alan Smith. In addition, John Salako has verbally indicated to Noades that he wants a move.Reuse content