Isinbayeva, Olympic champion in 2004 and 2008, had been due to return to competition on Saturday for the first time since the birth of her daughter in June, 2014.
She had to pull out of the Russian Grand Prix in her home city of Volgograd, however, after suffering a calf problem.
"Thankfully, this was not as bad as we originally thought," the 33-year-old told the Russian Athletics Federation's website (www.rusathletics.com).
"This means that I don't need an operation and I will undergo a normal process of trying to get better. This will take around four weeks. Of course the winter season is over for me, but I am optimistically looking forward to summer," Isinbayeva added.
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Isinbayeva's hopes of competing in this year's Olympics were hit when Russia was suspended from world athletics last November following allegations of widespread and state-sponsored doping in a report by the World Anti-Doping Agency (WADA).
The new head of Russia's Athletics Federation, Dmitry Shlyakhtin, said after his election last month that his top priority was to get the country's athletes to the Games in Rio de Janeiro.
(Reporting By Dmitriy Rogovitskiy, editing by Ed Osmond)
