FIFA closed the door yesterday on two German clubs' hopes of stopping their Brazilian players from going to the Olympics.

After the Brazil squad for Beijing was announced Tuesday, Werder Bremen said it would not release 23-year-old midfielder Diego, and Schalke resisted giving up its 22-year-old defender Rafinha.

World football's governing body responded by restating its rule obliging clubs to release players aged 23 or under, "in view of the importance of the Olympic Tournament for the entire sporting movement in general and football in particular."

"The release of players younger than 23 has always been mandatory for all clubs," FIFA said in a statement. "For Beijing 2008 the same principle shall apply."

The German clubs claim the month-long Olympic commitment of training and matches clashes with the start of the European season.

Both clubs say the players would miss two Bundesliga games. Schalke has a Champions League qualifying-round match scheduled for August 12 or 13.

Clubs are not forced to release players over the age of 23, though Spain's FC Barcelona is trying to stop Ronaldinho participating as part of an ongoing dispute with its Brazilian superstar.

Each of the 16 competing nations can name three overage players on its roster.

"The release of these players is not compulsory, according to the FIFA regulations," the organisation said.