British hurdler Jack Green has been forced to pull out of the World Championships in Beijing due to an onset of sciatica.

The 23-year-old was initially only named in the men's 4x400m relay squad after returning to fitness following a two-month absence due to injury.

The athlete was then added to the 400m hurdles event after appealing his omission, but he has suffered another setback and will not compete in China.

"I'm disappointed but experience tells me that I have to look forward to what is next and turn every experience into a positive one," Green said in a statement. "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."

The Championships will get underway on Saturday.