David Rudisha didn't take part in the Kenyan trials that ended Friday and will miss this month's world championships as he struggles to get over thigh and back injuries that have kept him out of top-level competition for more than two years.

The 800-meter world-record holder and two-time Olympic champion said he wasn't ready for the worlds in Doha, Qatar, but is aiming to return to competition at the start of next season in preparation for the Tokyo Olympics. The 30-year-old Rudisha, who last ran in a major race in July 2017 and also missed the last world championships, denied recent reports he was going to retire. Instead, he was planning a "big comeback" at next year's Olympics, he said.

"I'm not done yet," Rudisha said. "Winning a third Olympic gold medal next year is a big motivation for me. Of course, it will not be easy, we have so many good guys in the 800 meters, but I will try my best to be ready for Tokyo.

"I have taken my recovery slowly over the last two years,"

Rudisha also said he was "fine" after escaping unhurt from a car crash last month, when his SUV collided with a bus.

Rudisha watched Friday's action at the Nyayo National Stadium in Nairobi, where Kenya announced a 49-member preliminary squad for the worlds after the two-day trials.

The team has four athletes who won gold two years ago in London. Elijah Manangoi (men's 1,500 meters), Conseslus Kipruto (men's 3,000 meters steeplechase), Faith Chepng'etich Kipyegon (women's 1,500) and Hellen Obiri (women's 5,000) will all defend their titles in Doha.

Manangoi didn't run at the trials because of injury but was given a place on the team. Kipruto pulled out of his race in the sweltering heat in the Kenyan capital but also has a place on the team.

Manangoi's younger brother, George, made the team after finishing third in the 1,500 and the siblings are set to run in the same race at the worlds.

Four runners who qualified for the team will have to wait for clearance from the IAAF and the Athletics Integrity Unit because of anti-doping regulations.

Men's 5,000-meter runners Daniel Simiyu and Nicholas Kimeli and women's 1,500 runners Sela Jepleting and Judy Chepng'etich have not met the requirement that athletes from nations on the IAAF's doping watchlist be tested at least three times before the worlds to be eligible.

Trials director Barnaba Korir said the Kenyan track federation has written to the AIU asking that the four be tested in the next two weeks before the worlds begin on Sept. 27.

None of those four have ever been accused of any wrongdoing but Kenya has had its reputation eroded by dozens of doping cases in the last few years

"It is not about only winning but doing so with clean athletes," Korir said. "We hope the team we will take to Doha will not have any problems with doping."

Kenya won five golds and 11 medals overall at the last world championships in London, the second-best team behind the United States.

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