Injured Powell pulls out of Aviva London Grand Prix

The would-be king of the sprint world was a notable absentee from the opening night's action at the Aviva London Grand Prix here at Crystal Palace.

Asafa Powell, ahead of his Jamaican compatriot Usain Bolt at the top of the world rankings this year, announced his withdrawal from the field for the 100 metres yesterday morning.

"I have had some tightness in my groin since I raced in Budapest last weekend," Powell said. "I had hoped that it would have cleared by now but it is still there. I am only focusing on the World Championships in Daegu. As much as I would love to run tonight, I just can't risk anything with Daegu three weeks away."

Although a disappointment to the organisers and to the Crystal Palace crowd, injury having already ruled out Tyson Gay, Powell's decision was entirely understandable. The 28-year-old has been undermined by injury before in the lead-up to major championships and will need to be on top of his game to challenge Bolt for the world title in South Korea.

Powell's agent Paul Doyle added: "We've made the decision not to race tonight as a precaution. Asafa has a tightness in his groin that has been getting better every day, but to run tonight would put him at risk of injury. If we had two or three more days, I think he would be fine and able to race, but unfortunately that is not the case."

At least Powell has his place in the Jamaican team for Daegu assured. After finishing fifth in the discus at the domestic trials meeting in Birmingham last Sunday, Lawrence Okoye needs to raise his game on the second day of the Crystal Palace meeting today if he is to make the British squad.

These are beguiling times for the giant young Croydon Harrier, who stands fifth in the world rankings, ahead of Olympic champion Gerd Kanter, courtesy of the monster 67.63m British record distance he threw at the UK Athletics Throwsfest meeting in Hendon a month ago. The two automatic places in the British team having been claimed by Abdul Buhari and Carl Myerscough, the 6ft 6in, 20st Okoye faces a battle with Welshman Brett Morse today in the race to claim the final spot.

"It's either win or bust for me at the moment, from one extreme to the other," he reflected. "Hopefully, these inconsistent times will go away soon and I'll be able to produce big throws every week. The discus is a really technical event. It's hard to master. But I'll get there.

"In the meantime I'll just see what I can do. If I throw badly again this weekend and don't go to the World Championships, it's not going to be any skin off my nose. I'll just get back into winter training early and, hopefully, come out flying next year.

"If I throw well this weekend, then great. I'll have another chance to do something big this year. We'll just see what happens."

It bodes well for Okoye's long-term future in track and field that he can maintain such a balanced perspective on his potentially disorienting situation. At 19, he is still learning the ropes of the discus under the guidance of the seasoned throws guru John Hiller.

It was only last summer, after finishing sixth at the World Junior Championships, that Okoye decided to concentrate on track and field rather than rugby union. He was formerly a member of the London Irish Academy and scored for the victorious Whitgift School in the English Schools' Cup final at Twickenham last year. He also chose to defer a place to study law at St Peter's College, Oxford, to train full-time as an athlete until the 2012 Olympics.

Given Okoye's inexperience as a discus thrower, the inconsistency that has bedevilled him all summer has been understandable. It does not eclipse the huge potential his British record throw at Hendon measurably demonstrated.

"They say it takes about 10,000 throws before you can call yourself a discus thrower," Okoye said. "I do about 250 a week, so I've got a long way to go before I can call myself one properly. It's just a matter of practice and experience and that comes with age.

"There is no need for anyone to be disappointed in how I did last weekend because it's always going to be like that at this stage. When I do actually get into my prime, and the sort of age where I know I can produce big throws on a regular basis, that's when I'll be a world-beater. But at the moment I'm just one of those guys who can do something big or do something really badly."

In addition to Okoye, Morse and Kanter, the line-up for the discus this afternoon includes the triple Paralympic world champion Dan Greaves from Loughborough. He will be throwing with a lighter implement.