Dean's season has been blighted by injury
British steeplechaser Hatti Dean has withdrawn from the Games after failing to recover from an ankle injury.
The 26-year-old was named in the British team despite being ruled out of July's Olympic trials because of a stress fracture to the ankle.
But despite three weeks of aqua jogging, she has felt more pain in the ankle and has decided to withdraw.
"It is very disappointing, I feel like I am fit, but the ankle is unable to handle running quite yet," she said.
"I will now go back to running in the water.
"I don't think I'll be ready to race on the track again this year. I will just have to focus upon the cross country season this winter."
Helen Clitheroe and Barbara Parker will line up for Britain in the women's 3000m steeplechase in Beijing, the heats of which take place on 15 August.