BRISBANE, Australia (AP) -- Regina Jacobs, considered a top medal contender in the women's 1,500 meters, has withdrawn from the Olympics because of a respiratory infection.

 Jacobs and her coach and husband, Tom Craig, made the decision Friday at their home in Oakland, Calif.

 "I have had problems with my breathing and lung capacity since racing at the Golden League meet at Zurich (Aug. 11)," Jacobs said in a statement released Saturday (Friday night EDT) by Nike. "As a result, I was feeling very fatigued and sluggish."

 Jacobs said her condition appeared to be improving until Tuesday, when "I had a relapse and couldn't even complete my workout.

 "I had hoped to get it under control before Sydney, but we seemed to have run out of time. Further, Tom and I felt that competing at Sydney could put me at risk of injury.

 "Obviously, I'm very disappointed and wish I could be competing in Sydney. These things happen and now I just have to focus on the future."

 Jacobs said she would be in Sydney to support the U.S. team.

 Her agent, Emmanuel Hudson, also expressed disappointment.

 "I was very sorry to get the call from Regina yesterday," he said. "She was a favorite for a medal and it's a very unfortunate situation for her. It's a big loss for U.S. track and field and the Olympic team."

 U.S. women's coach Karen Dennis said a replacement had not been picked, although the logical candidate would be Shayne Culpepper, the fourth-place finisher at the U.S. Olympic trials in July at Sacramento, Calif. Culpepper's husband, Alan, is a member of the 10,000-meter team.

 The other members of the 1,500 team are Suzy Favor Hamilton and Marla Runyan.

 Jacobs was one of the stars at the trials, winning the 1,500 and setting the U.S. record in the 5,000 meters. She opted to withdraw from the 5,000 for the Olympics to concentrate on the 1,500, in which she won the world indoor title in 1995 and was the world outdoor silver medalist in 1997 and 1999.

 This would have been Jacobs' fourth Olympics. In 1988 and 1992, she failed to make the 1,500 final and in 1996 she finished 10th.

 Jacobs, 37, also has won the U.S. 1,500 outdoor title eight times, including last year when she also doubled in the 1,500 and 5,000. She also was the 1999 world indoor bronze medalist at 3,000 meters.