Kenya's hopes for a gold medal in the 800 meters at the World Championships have been weakened.

David Rudisha's plan to add another 800 metres gold to the Olympic title he won in a world record time on the same track in 2012 have been dashed due to injury.

The 28-year-old -- who ran an astonishing time of 1min 40.91sec to take gold in 2012 -- took to Twitter to reveal he could not take his place in the London Stadium for the championships.

"It's sad and disappointing to announce my no show in the forthcoming #london2017 WC due to a quad muscle strain," tweeted Rudisha, who was the defending champion.

The absence of the two-time Olympic champion -- whose run in 2012 was acclaimed as the standout performance of the Games by London 2012 chairman and athletics great Sebastian Coe -- could pave the way for compatriot, Emmanuel Korir or the man who chased him to the finish line in London, Nijel Amos of Botswana.

The games begin on Friday.