American double world champion Sam Kendricks will not defend his pole vault title in Eugene, Oregon, later this month after his recovery from surgery took longer than expected, his agent said on Wednesday.

The 29-year-old has not competed since April and had knee surgery on May 2.

"Although we hoped he would be at 100% for the World Championships, it has been a slower healing process than we expected," Kendricks' agent, Paul Doyle, told Reuters via email.

READ: Vetter out of World Athletics Championships with shoulder injury

"Sam felt his time would be better spent rehabbing to get (ready) for meets post world championships."

The news marks the latest disappointment for the Rio Olympic bronze medallist, who missed out on competing at the Tokyo Games after testing positive for COVID-19.

He produced a vault of 5.97 metres to win in 2019 and collected gold in 2017 with a leap of 5.95 metres.

Also on Wednesday, 2017 javelin world champion Johannes Vetter of Germany said he would also miss the world championships, set to run from July 15.