BEIJING - Li Na, the first Chinese to reach the quarter-finals of a grand slam at Wimbledon last year, has pulled out of this year's event because of injury, the Chinese Tennis Association (CTA) said on Friday.

The 25-year-old, China's best hope of a singles gold medallist at next year's Beijing Olympics, has been replaced as 18th seed by France's Marion Bartoli.

"She was injured in her rib region during (the warm-up event) in Birmingham," the Chinese Tennis Association (CTA) said in a statement.

"Medical staff have suggested she stops all training and competition to rest and heal."

Zheng Jie, who won the women's doubles with fellow-Chinese Yan Zi at Wimbledon last year, had already been forced to withdraw from the tournament because of an ankle injury.