Lynsey Sharp and Caster Semenya clash in Doha Diamond League

Lynsey Sharp will bid to reset her career following 12 months of disappointment, starting with tonight’s opening Diamond League leg in Doha.

Caster Semenya, right, shakes hands with Lynsey Sharp at the 2017 World Championships in London. Picture: Jewel Samad/AFP/Getty Images

The eyes of the sport will be on the 800 metres after Caster Semenya was added to the start list yesterday, 24 hours after the South African lost her legal challenge against the IAAF’s new rules regulating testosterone levels for female athletes.

The Qatari meeting is the last before the revamped measures are imposed next week, forcing the Olympic champion to decide whether to take hormones to lower her count or face exclusion from her favourite event.

The South African was not at a press conference yesterday to hear IAAF president Sebastian Coe welcome the Court of Arbitration for Sport’s verdict as upholding the principle that fair competition in women’s sport should be protected.

But she posted a strongly-worded message on her Twitter account, saying: “They laugh at me because I am different. I laugh at them because they’re all the same.”

Coe backs the CAS ruling because he believes it endorses the principle of a level playing field. “It is very straightforward for any international federation in sport,” he said. “Athletics has two classifications: it has age, it has gender. We are fiercely protective about both. And I am really grateful the court of arbitration for sport has upheld that principle.”

Semenya’s surprise late inclusion adds an extra dimension for Sharp who has radically revamped her routine after missing out on a medal at last summer’s European Championships and failing to earn a spot on the British team for March’s Euro Indoors in Glasgow.

The 28-year-old Scot – who wrote her university dissertation on the subject of inter-sex athletes in sport – has been the subject of further online abuse this week as a result of past comments suggesting that Semenya held a clear advantage over her rivals. But her attention will be on regaining her prime form and after splitting with her San Diego-based coach Terrence Mahon in the spring, it has been confirmed that the 2012 European champion is linking up with British Athletics in-house mentor David Harmer in a return to her previous base in Loughborough.

The Scot has sweated out at a training camp in Portugal ahead of a summer opener that also pits her against Olympic silver medallist Francine Niyonsaba – another athlete who has confirmed she has differences in sex development – and American Ajee Wilson. And Sharp acknowledged that, in a campaign that will culminate with the world championships back in Doha, ending a five-year medal drought has become the priority.

“That is what is important at the moment,” she said. “There is no point being in making teams just to be there. I want to be there to compete in medals.”

Despite the extra lengthy season, several British stars will get their campaigns under way today with European champion Dina Asher-Smith going in the women’s 200 metres, Nethaneel Mitchell-Blake racing the men’s 200m and Shara Proctor facing Lorraine Ugen in the long jump.