Dinara Safina has retired from professional tennis, her brother Marat Safin has revealed.
The former world number one, currently ranked 129th, is stepping down from the sport in large part due to a chronic back problem.
"Dinara has decided to end her career," former men's world number one Safin said.
"She has taken the decision relatively well. She considers it just to be the end of a period in her life.
"Everything is alright with her health. She feels good in everyday life, but [the back injury means] she simply can't play tennis professionally anymore."
The 25-year-old, whose last WTA appearance was April's defeat to Julia Goerges in Madrid, has 12 tour singles titles to her name.