JOHANNESBURG -- Caster Semenya withdrew from the World Student Games because of a back problem two weeks before she is to defend her 800-meter title at the world championships.
Glen Bentley, chairman of University Sports South Africa, told The Associated Press on Thursday that Semenya met with a team coach and manager last week to tell them she wouldn't be able to compete at the Chinese meet, which starts Friday.
"She said it's a niggling problem that may potentially lead to an injury," Bentley said. "In the national interest, we support the (withdrawal) idea so she can defend her world title. It's in her best interests and the interests of the country."
The 20-year-old Semenya was not part of the South African team that left for Shenzen on Wednesday. Instead, she will continue her preparations at a training base at University of Pretoria, Bentley said.
"She is rehabbing and training with caution," he said.
The worlds start Aug. 27 in Daegu, South Korea.
Semenya has struggled this season, only twice going under two minutes in 13 races. She ran 1:55.45 to win at the 2009 worlds as an 18-year-old in Berlin before she was sidelined for 11 months in a gender-test controversy.
Semenya returned in July 2010 after being cleared to run again by the International Association of Athletics Federations but has struggled to rediscover that pace.
She has been troubled by back problems, forcing her to miss the Commonwealth Games in India at the end of 2010.
Semenya was impressive in winning the 800 and 1,500 double at the South Africa nationals in April to kickstart her season but has failed to make significant progress in international competition.
She ran a 2:01.28 to finish eighth in the Diamond League event last month in Stockholm, her last competitive race.