Caster Semenya's silver has given South Africa its most successful Olympic Games since its reintroduction to international sport.
Semenya enters a race against time to qualify for this year's International Association of Athletics Federations (IAAF) World Championships.
The 22-year-old 800m specialist was adjusting well after undergoing rehabilitation for a recurring left knee injury, Harkonen said on Tuesday.
"She is recovering very well and practice is going well," he said.
Semenya had struggled with an imbalance in her leg strength since she was a child, according to Harkonen.
"The knee injury is a very old one that she picked up when she was young – about 12 years old – when she was in Limpopo.
"That operation was not a very good one and the knee has been a big problem during all these years."
However, extensive rehabilitation seemed to have rectified the problem, and Semenya was eager to return to the track after 10 months on the sidelines.
Olympic silver medalist
Perhaps South Africa's most successful track athlete in recent years, Semenya has not competed since she clinched the silver medal at the London Olympic Games in August.
She has performed consistently in championship events since rising from relative obscurity to win the women's two-lap title at the 2009 IAAF World Championships in Berlin.
Two years later, after bouncing back from a gender controversy, Semenya grabbed the silver medal at the global championships in Daegu, and while she showed relative immaturity in her tactical approach in the Olympic final, she again stepped on the podium.
"She has done lot of rehab to get that leg as strong as the other one, and now the power of the legs are nearly the same," Harkonen said.
"We have not decided yet on races, but if all goes well she will start to compete in late July."
The qualifying window for the global championships in Moscow, in August, closes on July 29, and Semenya will hope to add her name to South Africa's growing list of qualifiers.
Qualified
Long jumper Khotso Mokoena, an Olympic silver medallist, was the latest athlete to qualify when he leaped a season's best 8.3m in Bad Langensalza, Germany, on Saturday.
According to the IAAF A-standard criteria, 32 SA athletes have qualified in their events to compete at the global showpiece.
However, 10 of those athletes are male marathon runners, and only five athletes from the same country can compete in that event.
Six others – Simon Magakwe (100m), Lehann Fourie (110m hurdles), Burger Lambrechts (shot put), Victor Hogan (discus throw), Chris Harmse (hammer throw) and Lebogang Shange (20km walk) – have not achieved the A-standard marks in their events, but qualify automatically as African champions in their disciplines. – Sapa