MoreThe Meaning of Li NaLi Na, the Chinese sporting superstar credited with buoying the prestige of Asian tennis to Gram Slam heights, announced her retirement on Friday, citing long-term and worsening knee injuries. “Representing China on the tennis court was an extraordinary privilege and a true honor,” wrote Li in a letter to fans posted to Facebook. But, she said, “my body is begging me to stop the pounding.” “As hard as I tried to get back to being 100%, my body kept telling me that, at 32, I will not be able to compete at the top level ever again,” said Li, who has had four knee surgeries.