Kenya's Emmanuel Korir is confident of clocking a world record in an 800m race－he's just not sure when.

The 23-year-old, who trains in the United States, believes he has the strength to challenge－and eclipse－Olympic champion David Rudisha's current record of 1:40.91.

Korir's personal best is 1:43.10, which he set at the Monaco Diamond League meet last year.

"My goal this year is to run 1:42 or 1:41 and ... maybe a world record. When you have a dream and work on it, you will achieve it," Korir said on Wednesday.

"Maybe in four years' time I will be able to run a world record. My coach is always encouraging us to focus."

On Saturday, Korir will face a major test as the world's top runners head to Eugene, Oregon, for the Prefontaine Classic, the third stop on the Diamond League circuit.

"I have no specific target for the Prefontaine Classic or in the Diamond League, but you never know. I want to win or run a personal best," said Korir.

His coach and compatriot, former world 800m champion Paul Ereng, said Korir has the potential to break any record if he remains focused.

"Korir is in good shape but needs to race a little bit more. Last year by this time we had raced several races, but this year he has only raced twice and was unable to go to the World Indoor Championships in England because of visa issues," said Ereng.

"In Qatar, they started the race slowly and he only picked it up on the second lap. He should be ready to run a fast time in the Prefontaine Classic."

The Oregon field will be tough, with Botswana's Nijel Amos, Kenya's Kipyegon Bett, Commonwealth Games champion Wycliffe Kinyamal of Kenya and European winner Adam Kszczot of Poland among others lining up.

Korir won the Doha Diamond League meet on May 4, clocking 1:45.21, and also topped the list in New York, posting a season-best time of 1:44.21.

Rudisha sidelined

Meanwhile, double Olympic 800m champion Rudisha will skip the entire Diamond League season as he nurses a hamstring injury, which has kept him out of competition since last summer.

The 29-year-old Kenyan was expected to return to competition at the Shanghai Diamond League meet on May 12, but was unable to run. Several visits to doctors in Kenya and the Netherlands have yielded little success.

Rudisha's manager, Michel Boeting, said he does not expect the world-record holder to compete until August. That will leave him with little competition save for the Africa Athletics Championships in Asaba, Nigeria, from Aug 1-5.

"Rudisha is still dealing with an injury to his upper hamstring muscle. It stems from 2016, when he won Olympic gold in Rio, but it went undiagnosed for a long time and because he was constantly training, it did not have time to heal properly," said Boeting.

Rudisha, the only man to have run the 800 in under 1:41, recently returned home from the Netherlands, where he had gone to seek specialized medical treatment.

"It feels good to be back home," he said. "My focus will be on getting better and returning to the training track."

Boeting believes the long layoff will ultimately help Rudisha return to his best form and run at the top level. "David has finally taken the time to let the injury heal, and hopes to return to training in June," Boeting said.

"It is uncertain whether he will race this year, but if he does it would likely not be until August."

Xinhua