Estonian tennis star Kaia Kanepi has been forced to pull out of the Baltic nation's Olympic team due to a heel injury that also sidelined her from Wimbledon. "An ultrasound examination showed on Tuesday that Kaia's heels have not recovered as fast as hoped and she has to withdraw from the London Olympic Games," said a statement on the world number 16's website. "Her doctor Madis Rahu said that increasing practice intensity now would eventually lead to an even longer injury break," it said. Kanepi, 27, was one of the biggest names in Estonia's 34-member Olympic delegation and the country's lone London-bound tennis player. She also represented her nation of 1.3 million at the 2004 Athens Olympics and in 2008 in Beijing, reaching the third round of the latter."It's very sad that I cannot participate in the Olympics. I do not know if I will ever get another chance to participate in the Olympic Games. At the moment all I want is my legs to be ok and that I could play tennis without feeling any pain," Kanepi said on her website. She said her future tournament schedule is not yet clear, with a decision expected after she has more medical tests over the coming weeks. Kanepi, who in January won her second WTA title at the Brisbane International, was first hit by her heel injury at the Estoril Open in May, though she was in good enough shape to win the tournament. After a successful run at the French Open in June, where she went out to Maria Sharapova in the quarterfinals, she took an injury break in an effort to get ready for the Olympics. Kanepi has notched up a string of records for Estonia, which returned to the global sporting fold after the end of five decades of Soviet rule in 1991. She was the first Estonian to reach a WTA final at Hasselt in 2006, a Grand Slam quarter-final at the 2008 French Open, to crack the world top 20 in February 2009, and to win a WTA title in 2010 in Palermo. Estonia's main medal hopeful in London is Gerd Kanter, who won the discus gold in Beijing.