STOCKHOLM (AP) -- Two-time French Open finalist Robin Soderling is retiring at the age of 31 due to illness.
The big-serving Swede, who ended Rafael Nadal's 31-match winning streak at the French Open in 2009, has never fully recovered from contracting glandular fever in 2011.
Soderling, who rose as high as No. 4 and has a 310-170 win-loss ratio, reached the final at Roland Garros in 2009 and 2010.
He had hoped to return to competitive action next year.
Soderling wrote on the Swedish website tennis.se: "I want to inform you that I have decided to end my career as a professional tennis player ... I've realized that I will not be healthy enough to be able to play tennis at the level I demand of myself."
He won 10 singles titles.