British marathon runner Mara Yamauchi will miss this summer's World Championships in Berlin because of a foot injury.
The 35-year-old, who achieved selection for the GB team with her second-placed finish at the London Marathon in April, picked up the problem in training.
"I will not be able to race competitively in Berlin and have decided to withdraw," she said.
"I have been doing everything possible to help my foot to recover quickly."
Yamauchi finished sixth at the Beijing Olympics last year, and her London Marathon performance made her Britain's second fastest female over the distance after Paula Radcliffe.
"I have made a big breakthrough this year and was looking forward to the World Championships with great optimism," said Yamauchi.
606: DEBATE"This was a difficult decision to make as it is always a huge honour to race in a GB vest and represent your country.
UK Athletics head coach Charles van Commenee added: "Mara is an athlete of great talent, maturity and professionalism. She was also a true medal contender for Berlin and as such we will miss her presence."
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