Jack Green has been forced to withdraw from the IAAF World Championships in Beijing after suffering an onset of sciatica.
The 23-year-old had worked hard to regain fitness and secure his spot on the GB team having not competed since June through injury. He was initially selected just to the 4x400m relay squad but later appealed his omission from the 400m hurdles and was also named for the individual event.
"I'm disappointed but experience tells me that I have to look forward to what is next and turn every experience in to a positive one," said Green. "I didn't want to let anyone down but I have to accept that for now, this just isn't my time."
British Athletics performance director Neil Black added: "I really feel for Jack who put his all in to getting fit for the championships, to be struck with another issue unrelated to the previous one.
"It has been great to have him in the camp again and I'm sure he will be putting his focus into wintering well and coming into 2016 in a positive way."
Speaking to AW ahead of the championships, Green had praised the strength of the GB men's 4x400m squad, saying: "I'm not sure there’s been this much competition in the 4x400m for a long time."
The London Olympic relay finalist added: "Everyone is pushing themselves, not only for their individual events, but also to get that relay spot. I think the selectors will have a difficult time choosing."