Janko Tipsarevic, who has not played this season because of a left foot injury, has had surgery to try to correct the problem.
Tipsarevic was eventually determined to be suffering from plantar faciitis, and underwent the procedure on Wednesday.
"It was a complicated surgery (cause there was so much damage 'inside'), but it went well," he wrote on Twitter.
The Serb was originally expected to return at Dusseldorf ahead of playing the French Open, but pulled out of the event and and announced he would be having surgery. He has not given a date for his return.
But the former world No. 8 has had plenty going on off the court this year, having become a father for the first time and launching his own tennis academy in Serbia.