Eugene - Veteran US sprinter Carmelita Jeter on Thursday pulled out of the Olympics after failing to recover from a quadricep muscle injury.
The 36-year-old 2012 Olympic 100 metres silver medallist announced her decision on her Instagram feed on the eve of the United States Track and Field Olympic trials.
"Unfortunately due to me re-aggravating my left quad I will not be at 2016 Olympic trials," Jeter said in a video message.
Jeter, from California, was a member of the American 4x100m relay team in London four years ago which set a world record en route to a gold medal.
She also won a bronze in the women's 200m in London.
Other key career achievements include a two gold medals at the 2011 World Championships in Daegu, South Korea, where she won the 100m and 4x100m.
Her preparations for the Rio Olympics had been disrupted by injuries which left her an outside bet to make the team.
"It's been a rough two years for me, with two torn quads and a quad surgery," Jeter said on Thursday.
The July 1-10 US Olympic trials begin on Friday at the University of Oregon's Hayward Field stadium.
Meanwhile US distance runner Nick Symmonds, who had vowed to run with black tape on his kit in Eugene in a protest against marketing restrictions placed on athletes during the Olympics, also withdrew on Wednesday.
Symmonds had been struggling to recover from an ankle injury and on Thursday admitted defeat in his battle to be fit for the trials, where he was aiming to challenge in the 800m.
"This ankle has taken me to 2 Olympic Games, but it will not take me to a 3rd," Symmonds wrote on Twitter underneath a photo of his left ankle.
"Forced to withdraw from Olympic Trials."