Former world 100m champion Yohan Blake will miss the rest of the season after having surgery on an injured hamstring.
The 24-year-old double Olympic silver medallist suffered the injury in the 100m at the Glasgow Grand Prix in July.
Blake's coach Glen Mills said: "Right now he's on crutches. He had to have an operation a couple of days ago."
The Jamaican had already opted not to take part in the Commonwealth Games in Glasgow as he said he could not put his preparations for Rio 2016 at risk.
He has suffered from a succession of hamstring injuries and was unable to defend his 100m world title in Moscow last year.
"I am down but just a little," Blake said in a Facebook message. "I'm still going to fight even harder for everyone who continues to support me. I feel I owe it to the sport and the fans."
Mills added: "The injury was quite severe and the original prognosis was misdiagnosed and he went to Germany and when they had a good look, they realised that it was more serious and required surgery, so he'll be out for quite a long time."