Serena Williams has been nixed in mixed.
Williams won't play mixed doubles at the London Olympics, and the two US teams will instead feature four doubles specialists - the Bryan brothers and Liezel Huber and Lisa Raymond.
"We all discussed it," US coach Mary Joe Fernandez said on Tuesday. "I think it was the best decision for the team."
Raymond and Mike Bryan will be reunited after winning their third Grand Slam title together at Wimbledon this summer. The other US entry will be Huber and Bob Bryan, who have won two major titles together.
Other entries for the competition beginning Wednesday include Lleyton Hewitt and Samantha Stosur of Australia, Victoria Azarenka and Max Mirnyi of Belarus, and Juan Martin del Potro and Gisela Dulko of Argentina.
Williams, who is competing in singles and with her sister Venus in women's doubles, had repeatedly said she also wanted to play mixed doubles. Andy Roddick, John Isner and the Bryans all sought her as a partner.
But she became coy about the subject in recent weeks. Teams were entered Tuesday by each nation's Olympic committee, and Fernandez said three events might have stretched Williams too thin.
"It's a lot of matches in a short amount of time," Fernandez said. "You don't want to jeopardize the other events. We're lucky we have so many possibilities in matchups."
Venus Williams wasn't expected to play mixed doubles because she's already in two other events and dealing with an autoimmune disease that causes fatigue.
She said she and Serena will be glad to concentrate on singles and their doubles partnership.
"We already have a ton of matches ahead of us in just a few days, so I think it was better for us to focus on these two events," Venus said.
Mixed doubles is in the Olympics for the first time since 1924. Competition involves 16 teams, meaning only two victories are needed to reach the medal round.
Serena Williams has played little mixed doubles since early in her career. In 1998 she teamed with Max Mirnyi at Wimbledon and the US Open to win her only major titles in the event.
While the US entries lack the anticipated star power, they'll be formidable. The Bryan twins are competing as a team in men's doubles and seeded No. 1. The Huber-Raymond partnership is seeded No. 1 in women's doubles.
"What's most important is bringing home medals for the US," Venus Williams said.