Ana Ivanovic pulled out of the Generali Ladies with a left hip injury on Wednesday, one day after receiving medical treatment during her first-round win over Pauline Parmentier of France.
In a statement on the tournament website, the two-time former champion from Serbia says, "This injury has been plaguing me the whole summer, and it got worse during the recent tournaments in Asia. I am sorry but I can't play on."
Ivanovic, who was seeded second, defeated Parmentier 6-3, 6-2 but asked for a medical time-out while trailing 2-1 in the second set.
The eighth-ranked Ivanovic, who won the indoor hard-court event in Austria in 2008 and 2010 and reached the final last year, has qualified for the WTA Finals in Singapore in November.