Marion Jones has withdrawn from a pre-Olympic meet this week in London, where she had been scheduled to compete in the 100 meters and long jump.

Jon Ridgeon, a spokesman for Friday's Grand Prix meet at the Crystal Palace track, said organizers were informed Tuesday that Jones would not be competing.

Officials at Vector Sports Management, the Dallas-based firm that represents Jones, declined to comment yesterday.

Jones, a three-time champion at the 2000 Olympics, has qualified for the long jump at the Athens Games but also hopes to run on at least one U.S. relay team. She failed to qualify in the 100 at the recent U.S. Olympic trials and dropped out of the 200, citing fatigue.

She plans to run the 100 at a meet in Zurich on Aug. 6. She also is set to run in a relay in Munich on Aug. 8.

Jones is under investigation by the U.S. Anti-Doping Agency, though she has not been charged with drug use. She repeatedly has denied using performance-enhancing substances.

A report in the San Francisco Chronicle last week said her ex-husband, C.J. Hunter, has told federal agents that Jones was using banned drugs before, during and after the 2000 Olympics.

A Visit From Dean Smith

Former North Carolina basketball coach Dean Smith, who directed the U.S. Olympic team in 1976, dropped in on the U.S. men's team's practice yesterday in Jacksonville, Fla., chatting with Olympic coaches Larry Brown and Roy Williams.

Brown said Emeka Okafor was expected to have an MRI exam yesterday to determine the extent of the ankle injury he suffered Tuesday. Tim Duncan was fully recovered from a bout of stomach flu.

Brown said Duncan, Richard Jefferson and Allen Iverson, returning members from the national team that qualified the United States into the Olympics last year, likely will be starters at the Olympics.

Jamaican Star Sidelined

Lorraine Fenton, the 2000 Olympic silver medalist in the 400 meters, has withdrawn from Jamaica's team because of a hamstring injury, officials said.

Fenton has not recovered from the injury that kept her out of competition for most of the season, said Bernie Panton, head of the Jamaica Amateur Athletic Association. Fenton was unable to compete in Jamaica's national trials in June.

The 31-year-old, among Jamaica's most consistent athletes the past four years, was one of her country's best medal hopes. She was the silver medalist at the world championships in France in 2003. Jamaican sprinter Usain Bolt also is struggling to recover from a hamstring injury. Athletics officials have not commented on whether Bolt, who holds the junior world record in the 200 meters, would be ready for the Olympics.