In the wake of yesterday’s rejection by the Court of Arbitration for Sport of her appeal against the IAAF’s planned eligibility regulations for female classification (athletes with differences of sex development), South Africa’s world and Olympic champion posted ambiguous tweets that hinted at retirement.

Also on the 800m startlist is the Burundi athlete who finished one place behind her at the Rio 2016 Games, Francine Ninyonsaba, who last month confirmed she had a similar physical make-up to the South African.

Both are expected to run.

As of May 8, the IAAF requires female athletes falling into the DSD category to take medication that will lower their testosterone levels to below 5 nmol/L.

"Knowing when to walk away is wisdom. Being able to is courage," Semenya’s tweet read.

"Walking away with your head held high is dignity."

One person responded to Semenya's tweet saying "never give up" while another called for her to "fight until the end".

But Semenya posted another tweet shortly afterwards that read: "That's me and will always be. I'm finished."

Unless athletes such as Semenya and Niyonsaba have already been taking such steps in anticipation of the CAS backing the IAAF, May 8 will mark a cut-off point for their season.

Whether either will take advantage of the IAAF’s waiving of its requirement for levels to be sub-5 nmol/L for at least six months, in order to allow athletes to compete in this year’s IAAF World Championships in Doha which start on September 28 remains to be seen.

The women’s 800m is thus likely to be a confusing event, from an emotional point of view, with, perhaps, an elegiac feel.

Were it not for the exceptional circumstances, the focus of interest in Doha would probably be on the fact that it is kicking off what will be the last of the original model meetings ahead of the proposed radical changes for next season.

Among the cast assembled, which includes six reigning world champions, eight reigning Olympic champions and winners of nine 2018 Diamond Trophies, are Caterine Ibarguen, the 2018 world athlete of the year, and world 5000m champion Hellen Obiri, whose star rose even higher just over a month ago at the World Cross Country Championships Aarhus 2019 where she earned impressive victory over the most difficult course in that event's history.

Obiri returns to the city where she broke the African 3000m record in 2014, clocking 8:20.68, still the fifth-fastest performance of all time.

That was at the Qatar Sports Club stadium, home to this meeting for its previous nine editions. 

This time she will take to the line about 13 kilometres to the south west, at the refurbished Khalifa Stadium in the city's Aspire Zone district which in less than five months’ time will host the IAAF World Championships.

Her chief opponent is long-time rival Genzebe Dibaba of Ethiopia, the world 1500m record holder who has captured the last three world indoor 3000m titles.

The men's pole vault sees world champion Sam Kendricks of the United States meet Brazil's 2016 Olympic champion, Thiago Braz.

Ryan Crouser, the Olympic champion from the United States, unleashed a 22.74m shot put in Long Beach, California, on April 20, the longest effort in the world since 1990, which elevated him to number six on the all-time list.

New Zealand’s world champion Tom Walsh admitted that had “annoyed” him.

The results could be interesting.

In the women’s 200m, triple European champion Dina Asher-Smith gets her season under way when she lines up as the favourite.