400m world record holder and reigning world champion Wayde van Niekerk will not compete at the 2019 IAAF World Championships in Doha, the sprinter announced on Monday.

Hey Guys. Here is an update on my come back. I’m so positive and just taking things day by day, respecting my body and when the opportunity comes, I’ll take it! No rush. Thanks so much for all your support! ? pic.twitter.com/gCmb0VpPcH

— Wayde van Niekerk (@WaydeDreamer) September 2, 2019

The South African, who was attempting a comeback from an Oct. 2017 ACL tear, had a setback in training earlier this year that delayed his timeline. He has since resumed training with his coach.

“For now I’m not rushing myself or putting pressure on myself. I’m extremely happy and at peace with where I am.”

Van Niekerk’s doctor, Louis Holtzhausen, said that the medical teams did all they could to get the 2016 Rio Olympic champion ready for Doha, “but it was just not possible,” he said.

“However, he has successfully returned to track training and all indications are that he will recover more rapidly from now on,” said Holtzhausen.

The 27-year-old raced just once in 2019, a 47.28 on Feb. 22. His last international competition was over two years ago at the 2017 IAAF World Championships in London.

Van Niekerk set the 43.03 400m world record in the Olympic final on Aug. 14, 2016.