Ireland’s Paul Hession failed to make it out of the heats of the 200 metres at the Olympic Stadium today.
The 29-year-old finished fifth in 20.69 seconds in a race won at a canter by Jamaican Yohan Blake.
Hession, who was 0.17secs off the third spot he needed to progress, said: “It is a little bit disappointing.
“I was hoping to push closer to third or second in that race. There were some serious athletes in there. That doesn’t mean I couldn’t beat them, but it wasn’t there.
“I was a metre away from where I needed to be to qualify.”
The former Olympic semi-finalist said it was the middle of the race that cost him.
Hession said: "I had a stacked heat to be honest, two world finalists and the second-fastest man in history in my heat, but I was right in the middle of them so that should be a good thing on paper, so that's no excuse anyway.
"The middle section is where I seemed to lose it, which is really a pity because in my 20.54 I was quite good in the middle section. I got out quite well and I finished reasonably well, but I was too far back."
Team-mate Fionnuala Britton ran a personal best of 15:12.97 in the heats of the 5,000m, but it was not enough to go through as she finished 10th.