Reigning Olympic champion Rafael Nadal has been forced to withdraw from the London 2012 Olympics due to ongoing knee problems.
Nadal, gold medallist four years ago in Beijing admitted he was "not in the right physical condition to compete" and that he had to "think about Spanish sport."
The world number three, who was due to carry Spain's flag at the opening ceremony, had already taken two weeks off in the buildup to the Olympics to recover from tendinitis in his knee
"I've waited until the final moment of my preparation and my training, but I cannot do it," Nadal said in a statement released to the Spanish press on Thursday.
"Today is one of the saddest days in my career. Carrying the flag for Spain at the opening ceremony was set to be one of the biggest honors, one of the most special moments for me. For this reason I hope you can understand how difficult it has been for me to take this decision. One of my teammates who is better prepared than me can take my place and compete to the best of his ability."
The Spanish Tennis Federation announced that world number 30 Feliciano Lopez would take Nadal's spot in the singles competition. Marc Lopez, who has won doubles titles with Nadal on the ATP tour, will take his place in the doubles competition.
The Spanish Olympic Federation have chosen basketball star Pau Gasol as the new flag bearer.