Olympic women’s marathon champion Peres Jepchirchir and distance runner Francine Niyonsaba will miss this month’s World Athletics Championships.
Kenya’s Jepchirchir has a hip injury, while Burundi’s Niyonsaba has a stress fracture.
Olympic and world 400 metres champion Steven Gardiner of the Bahamas will also miss the event in Eugene, USA, with tendon inflammation.
“The hip and the whole leg is painful,” Jepchirchir told Kenya’s The Nation.
Niyonsaba, Olympic 800m silver medallist in 2016, had been entered for the 5,000m and 10,000m races.
The 29-year-old was banned from competing in her favoured 800m distance in 2019 due to overly-high testosterone levels.
Meanwhile, Gardiner took to social media to explain his absence.
“Instead of putting on my spikes I’ve been advised to put on a walking boot,” he said in an Instagram post.
“Devastated by the news but I’m thankful for all the blessing in my career so far.”
Jepchirchir, 28, won the Olympic title in Tokyo last year in a time of two hours 27 minutes and 20 seconds, beating compatriot Brigid Kosgei and American Molly Seidel to take gold.
The 2016 and 2020 World Half-Marathon Championships winner added: “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 Games.”
Jepchirchir won on her Boston Marathon debut in April and was a late addition to Kenya’s four-strong team for the women’s marathon in Eugene.
Reigning world champion Ruth Chepngetich will race alongside Judith Jeptum and Angela Tanui.
Niyonsaba, meanwhile, said she had “no choice” but to withdraw from the championships on American soil.
“About one month ago, I had a beginning of a stress fracture. Me and my team did everything possible to recover,” she added in a post on Instagram.
“I am almost OK now but I couldn’t train for all this period, so I’m not in the shape that can allow me to perform the way I wanted.”
Niyonsaba, the only Burundian woman to win an Olympic medal, had success over 3,000m at the Doha Diamond League in May.
At last year’s Olympics, she finished fifth in the women’s 10,000m final with a national record, as she impressively adjusted to her ban from competing between 400m and 1500m because of naturally-high levels of testosterone.
The World Athletics Championships begin on Friday and last until 24 July.