Jonnie Peacock has confirmed that he will not defend his T44 100m title at next month's IPC Athletics World Championships in Doha.
The 22-year-old, who also won gold at the London Paralympics, has been advised to withdraw on medical grounds.
"Unfortunately I've had an ongoing problem with a sore on my leg, which will rule me out for the rest of the season," he said in a statement.
"It's something that I've been managing but it's now got to the point where I've been advised not to run on it. I'm extremely disappointed as this means I'll be unable to defend my IPC World Championship title."
The Championships get underway on Thursday, October 22.