David Rudisha has been forced to pull out of London 2017 in the stadium where he shattered the world record for the 800m.
The Kenyan, who took the record on his way to gold at London 2012 and won again last year in Rio, has withdrawn from the Kenyan team with a tear in his quad.
None of the 800m medallists from Rio will line up in London.
Explaining the injury, Rudisha said: “I was trying to engage more speed. In the process, I put my muscle under more stress ... I damaged my quad and this saddens and disappoints me a lot. If I push it with that pain, it could damage me further. I will still come back stronger.”
The 28-year-old is ranked only 19th in the world this year, but his absence still deprives the London championships of one of the sport's biggest stars.
Fellow Kenyan Emmanuel Korir and Botswana's Nijel Amos are expected to battle for the gold in Rudisha's absence.
The World Championships get under way at the London Stadium on Friday.