World 110 metres hurdles record holder, Aries Merritt of the United States will bow out after the 2020 Tokyo Olympics in 2021.
The Olympic Champion is yet to qualify for the Games which has now been moved to next year due to the global coronavirus crisis
Merritt, who won gold in the event at London 2012, will turn 36 on the second day of the Games if he makes the standard.
Merritt was diagnosed with a rare form of kidney disease, in 2013 after the World Athletics Championships.
He received a new kidney from his sister LaToya in 2015 four days after winning bronze at the 2015 Championships.
