Under-23 players must be released for the Beijing Olympics, world football supremo Joseph Blatter said in a statement issued on Wednesday.

'The release of players below the age of 23 has always been mandatory for all clubs. The same principle shall apply for Beijing 2008,' the FIFA boss Blatter said in a statement.

The statement said that Blatter sent an according letter to all member federations on the day.

'The fact that this tournament is not included in the coordinated international match calendar 'does not mean that there is no release obligation for the relevant clubs,'' the statement said.

'It would appear to be against the spirit of the Olympic regulations to hinder players under the age of 23, who are actually the core of the squads participating in the mens Olympic football tournament, to take part in the final phase of the event,' Blatter said.

Many clubs did not want to release players for the August 8-24 Games and German club Schalke even announced on Wednesday to bring the case of their Brazilian Rafinha before the Court of Arbitration for Sport.