STOCKHOLM — Robin Soderling was not sure where the paint should go.

In a cafe at the Kungliga Tennishallen here, Soderling talked with a tournament worker who was in charge of putting the Stockholm Open’s logo on center court. Time was important; the tournament was less than two weeks away.

“The TV cameras need to be able to see it,” said Soderling, who was once ranked as high as No. 4 in the world and played in two French Open finals.

Yes, the man with the paint replied, but where is it supposed to go? A few feet in front of the wall? A few yards? And which direction do the letters face? Soderling told the worker he would look into it right away. Then he sighed.

“Paint,” he said, smiling. He laughed. “This is my life now.”

It has been a strange six months for Soderling after an even stranger, and scary, three years. In 2011, he was soaring on the professional tennis tour, starting the year with three tournament victories in four events. But around Wimbledon, he began to feel sick: fever, chills and an overwhelming fatigue enveloped him. It felt as if his blood had been replaced by molasses, he said.