Having braved the global pandemic to travel from Launceston to Japan, the 26-year-old had a forgettable experience at the Yokohama race which had delivered him a silver medal three years earlier.

Birtwhistle said he regretted joking on social media about the water quality in Yokohama Bay.

"I shouldn't have jinxed it, but I guess I was right," he said on Instagram.

"I was sick all morning and wasn't able to get any fuel in so I just didn't have the energy to fight out there."

Birtwhistle and his international teammate Aaron Royle, of Newcastle, were both listed as "did not finish" in the race won by Norway's Kristian Blummenfelt in 1:44:55.

Birtwhistle, who has already secured a selection nomination for the Olympic Games in Tokyo later this year, will join up with his coach Joel Filliol and training partners.

"Off to Europe tomorrow to finally rejoin the #JFTcrew and get ready for the next one," he added.

The World Triathlon circuit also heads to Europe, with the 2021 World Triathlon Cup in Lisbon next weekend.

The next two rounds of the WTS hold fond memories for the 2018 Commonwealth Games gold and silver medallist.

Leeds (June 5-6) and Hamburg (July 10-11) both witnessed Birtwhistle wins when the series was last completed in 2019.

Other remaining rounds of the series are scheduled to be held in Montreal, Edmonton, Bermuda and Abu Dhabi.