Wayde van Niekerk: World champion will not defend title at World Athletics Championships
Olympic champion Wayde van Niekerk will not defend his world 400m title at this month's World Championships in Doha.
The 27-year-old South African returned to competition in February after more than a year out with a knee injury but had suffered a "minor setback" in his recovery.
He will miss the championships, which run from 27 September to 6 October, as a precaution.
"I'm positive and taking things day by day," Van Niekerk said in a statement.
"I am respecting all the calls made by the doctor and respecting my body. For me it is about listening to my body and taking it from there.
"For now, I am not rushing myself or putting pressure on myself. I'm extremely happy and at peace with where I am."
Van Niekerk suffered the injury in October 2017 during a celebrity touch rugby match, but made a winning return to action in February after almost 17 months out.
The world and Olympic 400m record holder had been aiming for a third consecutive world title in Qatar after being given a wildcard for the event.