The world's fastest man over 800m will not be able to contend for the world title this year. 

Nijel Amos, who ran 1:41.89 at the Monaco Diamond League meeting in July to set 2019's world-leading time and maintain it through the season, officially withdrew from heat two at the IAAF World Championships today less than an hour prior to its start time.

The Botswana athlete attributed his withdrawal to an extremely tight left Achilles tendon—a different injury than the one he sustained in his hamstring eight days following his scintillating Monaco showing that caused him to miss more than a month of competition. He returned at the Zurich Diamond League final on August 29 with a furious 48-second opening lap, but fizzled out toward the end to finish runner-up to Donavan Brazier in 1:42.98—still a world-class result that indicated he would be a top contender for the world title in Doha.

The 25-year-old has struggled in major championships outside of his silver medal as a precocious teen in the 2012 Olympic Games; Amos has not medaled on the global stage since, and this year will unfortunately be no different.

Keep up with more live updates from Doha right here.

Read: After 1:41 In Monaco, The Real Battle Begins Now For Nijel Amos

We spoke with Amos after his phenomenal 1:41.89 in Monaco—watch the full interview: