World javelin throw champion Julius Yego of Kenya says he will be seeking answers about his fitness level as he makes his first show in competitive action in Qatar on Friday at the Doha Diamond League.

It is over nine months since a limping Yego retired from the Rio Olympics suffering from an ankle injury that forced him out of the Games, reports Xinhua news agency.

It was his fourth attempt at the throw, which handed him the silver medal and won Thomas Rohler Germany's first javelin gold since Berlin 1936.

"I have been training since I recovered from the injury. This will be the first time I will see how I rank in competition and it will advise how my future training will be fine-tuned," Yego said on Tuesday in Nairobi.

With the focus being on defending his crown in London at the World Championships in August, Yego will carry no baggage as he returns to action, which leaves Rohler under pressure to prove he is the best in the sport at the moment.

The javelin rivalry will hit crescendo as the Olympic and World Champion face off though they will not be the only diamond in the ring.

Though Doha will serve as the curtain raiser for the Kenyan, it will not water down the spirit of competition as Yego seeks to take the battle to his opponent's door step.

"The focus in Doha is to gauge my fitness, how the body reacts to competition. I have done well in training throwing desired distance, but in competition, with all the pressure, it can change and that is what I want to confirm," he said.

"It will be great to battle against Thomas again. It is always great to compete against top athletes. I feel ready."

This will certainly be a dress rehearsal for the London Worlds and Yego did not shy away from throwing down the gauntlet to his opponents.

"I have been away in rehabilitation and now it's time to reap the great work done in the gym. This is to fulfil my dream of defending my title in London," he added.

But the Kenyan warned he might limit the number of competitions he will take part in on the build up to London as he seeks to consolidate his energy and avoid burning out.

"It is usually very tough to defend a title but this is my main goal this year," he said. "I also want to improve on my performance."