Phelps withdraws from 400m medley
INDIANAPOLIS, U.S. -- Michael Phelps has pulled out of the 400 meters individual medley at the world short course swimming championships with a sore back.
The American's withdrawal ends his bid to emulate his performance at the Athens Olympics in August when he won six gold medals.
Phelps, 19, won the 200 freestyle on Thursday but then told reporters he felt tired and sore.
The United States swim team issued a statement saying Phelps had been scratched from Friday morning's heats after complaining of tightness in his back.
Phelps will receive medical treatment and could still swim in the 4x200 freestyle relay -- the final event on a busy night of swimming that includes eight finals.
"I was really hurting pretty bad the final 75 meters, I was definitely in pain," said Phelps, following his race on Thursday. "My body has been beaten up pretty good in the last three months."
Distracted by sponsor commitments, endorsements and promotional appearances since his return from Athens six weeks ago, Phelps admitted to being far from his best coming into the championships and lacked his familiar power in his opening race.
If Phelps were forced to withdraw from the remainder of the championships it would be a major blow to organisers who were counting on his presence to help fill the stands.
The charismatic teenager is the main attraction of the five-day meet and was scheduled to swim in all 10 sessions in the temporary pool constructed on the floor of the cavernous Conseco Field House, home of the NBA Indiana Pacers.
He is also scheduled to swim in the 200 butterfly, and the 100 and 200 individual medley events.
With Phelps out of competition Australia's Adam Lucas was the top qualifier in the 400m individual medley, clocking a time of four minutes, 11.66 seconds.
Thompson to retire
Meanwhile, Jenny Thompson, who has won eight gold medals as part of various U.S. relay teams, has confirmed her retirement.
"The time has just flown by," said the 31-year-old. "I was doing the exact same ten years ago as I am now. I need a new hobby."
Thompson won 12 Olympic medals, including two silvers at the Athens Games but never managed to win an individual Olympic title.
Thompson will continue her medical career at Columbia University once the championships end on Monday.
