World number nine Lucie Safarova will skip the Australian Open because of health problems linked to a bacterial infection that saw her hospitalised for a week last September.
"The treatment of my bacterial infection has become complicated in recent days," Safarova said via a spokesman.
"I couldn't do the training that would allow me to fly to the tournaments in Australia well prepared," said Safarova, who won the doubles title at the 2015 Australian Open with Bethanie Mattek-Sands.
"That's why I have decided to pull out, not to burden the organism by travelling, and focus on treatment and gradual convalescence," the 28-year-old left-handed Czech added ahead of the year's first grand slam, which starts in Melbourne on January 18.
"My joints still hurt and so I can't prepare the way I and my coach would like."
"The bio-chemical checks are not a hundred percent either," she said.
After the infection, Safarova returned in time for last year's WTA Finals in Singapore, where she failed to make it past the group stage.
She was also on the Czech Republic team that won the Fed Cup in mid-November but did not play because of an inflamed tendon in her left wrist.
Safarova said she could possibly manage the first-round Fed Cup tie in Romania on February 6-7 if everything went well.
"If not, I will focus on the US tournaments on the WTA circuit (scheduled for March)," she added.