David Beckham has not been selected for the Great Britain Olympic football squad.
The 37-year-old former England skipper said in May he thought he had a "good chance" of playing at London 2012.
He said: "Naturally I am very disappointed, but there will be no bigger supporter of the team than me.
"I would have been honoured to have been part of this unique Team GB squad. Like everyone, I will be hoping they can win the gold."
Beckham made manager Stuart Pearce's shortlist of 35 players but was overlooked for the final 18-man squad as one of three players over the age of 23 allowed to compete in the Olympics.
Pearce, who watched Beckham play for Los Angeles Galaxy in the United States last week, picked Manchester City defender Micah Richards ahead of him.
Pearce rang Beckham on Wednesday night to tell him the news, explaining that he wanted more defensive cover in the squad.
Richards has been included alongside Manchester United midfielder Ryan Giggs and Liverpool striker Craig Bellamy as the three over-age players.
He played a major role as a sporting ambassador when London won the 2012 bid, and has made no secret of his desire to captain Team GB.
He said in April this year that he wanted to "be a part of history" by competing in the Olympics in his home town.
London 2012 chief Lord Coe said he would be talking to Beckham about a role during the Olympics.
"David has been an extraordinary supporter - probably our number one supporter - of the Games from the very beginning and is keen to continue his enthusiastic support right to the end," he said.
"He is from East London and knows how important the Games and sport are to young people. He is a great role model."
In January, Beckham said: "I have led my country before and know how special it would be to lead them into the Olympics."
However, Pearce said in April: "He's been a great ambassador but that's no guarantee he'll get in the squad. I'm picking on form and merit alone.
"David Beckham will be treated exactly the same as any other individual, whether it is young or over-age.
"I have a duty of care to the Great Britain squad to try to win a gold medal. I will pick the strongest squad I can."
BBC Match of the Day's Gary Lineker reacted to Beckham's omission by tweeting: (external) "Never thought for a second that David Beckham would be excluded from GB's team.
"Terrible shame for Beckham having given so much to the Olympic bid and football."
Former Wales international and BBC Sport pundit Robbie Savage tweeted: (external) "Why was Beckham on the shortlist in the first place, then not pick him? Disgrace!"
And Beckham's former England team-mate Danny Mills, who played under Pearce at Manchester City, told BBC Sport: "There's always an issue around the Beckham brand. We know how big he is - he's global, he's huge. But when it comes to football reasons, David Beckham can still do a job.
"I think he would have been a great spectacle and I think it's a bit of shame he's not in there.
"Stuart Pearce doesn't always like confrontation and he's struggled with big players in the past. Maybe he's thinking that what Beckham brings with him is too much to handle."
The British Olympic Association said it had not received the final 18-man squad from the Football Association.
A statement read: "We are expecting the list no later than the early part of next week."
Team GB were drawn in Group A at London 2012 alongside Senegal, Uruguay and United Arab Emirates.
They begin their Olympic campaign against Senegal at Old Trafford on 26 July before facing the United Arab Emirates at Wembley on 29 July, and Uruguay at the Millennium Stadium on 1 August.
Each squad must contain 15 players born after 1 January 1989.