Competition at the Lusail Multipurpose Hall is set to feature around 399 athletes from 69 countries.

Standout athletes include Riner in the men’s over-100 kilograms division.

The 31-year-old, who also has 10 world titles to his name, triumphed at London 2012 and Rio 2016.

He also went on an unbeaten run of 154 victories which lasted nearly 10 years, before Riner was finally vanquished by Japan’s Kokoro Kageura at last year’s Paris Grand Slam.

Other key contenders in Doha are expected to be Cuba’s London 2012 Olympic champion Idalys Ortiz in the women’s over-78kg and Japan’s four-time world champion Soichi Hashimoto in the men’s under-73kg.

With winners set to receive 1,800 world ranking points, the event in the Qatari capital will act as a qualification tournament for this year’s Olympics in Tokyo.

Qualifying resumed with the Budapest Grand Slam in October following an an enforced break due to the COVID-19 pandemic. 

Under the IJF's revised process for the postponed Tokyo 2020 Olympics, athletes have until June 28 to earn qualification points.

Competition in Doha is set to be held with strict health protocols in place.

Athletes will have been tested for COVID-19 on arrival and escorted to their hotel, where they are expected to remain for their entirety of their stay apart from training and competition. 

They will also be tested each day before the bouts begin.

"We are happy with the progress of things so far, and we are very impressed with the level of our preparation for the IJF World Judo Masters Doha 2021," said tournament director Eid Al Meraikhi.

"All arrangements are in place to ensure a smooth and stress-free tournament. 

"We are ready to host the world, and we believe all participants will leave Doha at the end of the competition with lasting memories. 

"Qatar is globally renowned for hosting very successful sporting events, and we are building on that reputation with this tournament." 

Action begins tomorrow and is scheduled to run until Wednesday (December 13).