Relay sprinter Debbie Dunn took her name off the U.S. Olympic team roster Friday after testing positive for excessive testosterone.
Dunn, who finished fourth in the 400 meters at Olympic trials, was selected for the American relay pool. She is the 2010 world indoor champion at 400 meters and would have been a likely candidate to run in the Olympic 1,600-meter relay, which the American women have won every year since 1996.
But she released a statement acknowledging a positive doping test and said she was withdrawing from the Olympics while the U.S. Anti-Doping Agency pursues the case.
No replacement was immediately named, and it may not be necessary to find another sprinter to take Dunn's place. Among the candidates to run in the 1,600-meter relay are the top three finishers in the 400 at trials - Sanya Richards-Ross, Francena McCorory and DeeDee Trotter, along with Diamond Dixon, Keshia Baker and Allyson Felix, who qualified for the 100 and 200 sprints but also has experience running at 400 meters.
