Wayde van Niekerk pulled up injured in his first race of the season in Italy on Saturday night, hopping off the track about 50 metres into his season-opening 200m race in Trieste.
The 2016 Olympic 400m champion and world record-holder pulled out of the SA championships in Cape Town last month because of a niggle.
Van Niekerk, who was eliminated in the semifinals at the Tokyo Olympics, has yet to find the form that took him to the top of the world before he injured his right knee in a game of touch rugby in 2017.
He has yet to prove that he can go three rounds in a championship at pace, or even get through a few meets without pulling out with an injury or concern over the threat of one.
The world championships in Eugene, Oregon, are scheduled to kick off on July 15, the day Van Niekerk turns 30.
But whether he will be ready for that remains to be seen.
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