Olympic women's marathon champion Peres Jepchirchir of Kenya will miss the World Championships in Eugene, Oregon, due to a right hip injury, her agent told Reuters on Monday.
Jepchirchir was one of the favourites for the title having also won the New York marathon last year as well as the Boston Marathon in April.
Kenyan news outlet Nation reported the 28-year-old runner first felt discomfort last week after which Team Kenya's doctor advised her to rest.
"For sure the hip and the whole leg is painful," she was quoted as saying by the African outlet.
"I am so disappointed but I would rather not aggravate the injury since we still have another world event next year before my Olympic title defence at the 2024 Paris summer Games."
Reuters has contacted Athletics Kenya for a statement.
Jepchirchir beat compatriot Brigid Kosgei and American Molly Seidel to win gold in Tokyo last year. Jepchirchir's compatriot Ruth Chepngetich is the defending world champion and has the fastest time this season.
The women's marathon at the worlds will be held on July 18.