Raul (left) is competing against Beckham in the battle for 2012
Real Madrid striker Raul Gonzalez has been named as an ambassador for Madrid's bid to host the 2012 Olympics.
Five-time Tour de France champion Miguel Indurain and former tennis star Arantxa Sanchez-Vicario are also among the 13 athletes promoting Madrid's bid.
Two of them will join Spanish Prime Minister Jose Luis Rodriguez Zapatero and Queen Sofia at the vote on 6 July.
Madrid is competing against London, Paris, New York and Moscow for the right to host the Games in 2012.
Raul's involvement will put him at odds with Real team-mates David Beckham and Zinedine Zidane.
It is essential to show we have strong institutional and popular support
England captain Beckham has appeared in a promotional video for London's bid, while Frenchman Zidane is backing Paris.
Zapatero is the first of the rival leaders to commit to attending the final vote in Singapore, while it was announced on Friday that Queen Sofia would lead the Madrid delegation.
"It is essential to show clearly that not only do we have a great project, but also strong institutional and popular support," said Madrid Mayor Alberto Ruiz-Gallardon. The International Olympic Committee vote takes place on the same day as the opening of the G8 summit in Scotland. British Prime Minister Tony Blair and French President Jacques Chirac are due to attend the summit at Gleneagles, but both are considering whether to travel to Singapore first to promote their bids.