NYON, Switzerland (AP)

Two football clubs fighting FIFA to stop their players from going to the Olympics said yesterday they are still hopeful of winning their case in court.

FC Barcelona and German club Schalke of Germany will team up at the Court of Arbitration for Sport (CAS) next week to challenge FIFA's rule that players aged 23 or under must be released to play in the Beijing Games.

Barcelona wants to keep Argentina's Lionel Messi at home, while Schalke doesn't want Rafinha playing for Brazil. Werder Bremen, who have lost Diego to the Brazil team, are also part of the CAS appeal.

"We will try because we think we are right," Barcelona football director Txiki Begiristain told The Associated Press. "FIFA told us we were to let him (Messi) go and we did. If CAS tells us again that he has to be with the club we will try to get back the player."

The clubs will argue in court that the Olympic tournament is not included on football's international match calendar and clashes with the start of their season.

FIFA says the calendar only reflects the schedule for the full national teams - those which include players older than 23 - and that the Beijing dates were set by the International Olympic Committee. The 16-nation tournament kicks off on Thursday.

"It is still a project so we cannot say everything about it," Schalke spokesman Moritz Beckers-Schwarz said about the appeal. "But we are expecting we are on the right way."

Barcelona and Schalke officials were talking at the draw for the Champions League's third qualifying round, held at the headquarters of European governing body UEFA.

Both clubs want their players back for the first leg of a tie scheduled to be played August 12 or 13. Barcelona will play Beitar Jerusalem of Israel or Poland's Wisla Krakow; Schalke have a more difficult home-and-away match against Atletico Madrid.

Beckers-Schwarz said Schalke are worried that even if they win the CAS ruling - expected by next Tuesday - Rafinha might be upset about the decision.

"The Olympics is starting next week, and for the players to come back they will not be so happy," he said. "They will be sad to come back. It is a very difficult situation for the players and also the clubs."

Begiristain said Barcelona does not expect problems with Messi.

"In the preseason games he played with a wonderful attitude ... with intensity," he said. "I have never seen an unhappy Lio playing for our club."