Hong Kong tennis fans were left disappointed yesterday when Li Na withdrew from next Monday's showdown with Danish star Caroline Wozniacki because of the ankle injury she sustained in last month's Australian Open final. Chinese favourite and world No 5 Li was to play No 10 Wozniacki in the BNP Paribas Showdown at Asia-World Arena on World Tennis Day. She will be replaced by Wimbledon finalist and world No 4 Agnieszka Radwanska from Poland. "I am very sad that I won't be able to play in Hong Kong," Li said. "Unfortunately, the ankle injury I had in the Australian Open final is still not ready for me to compete. I know I have some of the best fans in Hong Kong and I was looking forward to playing for them. I promise I will be back next year." Earlier this month Li, 30, pulled out of the Qatar Open because of the same injury. She injured her left ankle during her 4-6, 6-4, 6-3 loss to Victoria Azarenka of Belarus in Melbourne last month. Li fell twice, rolling her left ankle both times. On the second tumble, she fell awkwardly and hit her head on the court. It did not come as a huge surprise that she would not play in Hong Kong. "It is very unfortunate Li has to pull out and I know no one is more disappointed than she is, but I am very pleased to be able to welcome Agnieszka," event promoter Jerry Solomon said. "The injury Li incurred in the final of the Australian Open last month has not responded enough to intense treatment. We send Li our best wishes for a speedy recovery and look forward to seeing her playing next year." Five months after playing an exhibition match here in 2011, Li went on to capture the French Open, becoming the first Asian player to take a grand slam singles event. She had earlier thrown her support behind Hong Kong when told the city would next year host its own WTA event, breaking a professional tournament drought that dates back a decade. The Hong Kong Open will be staged from September 8 next year, a week after the US Open finishes in New York. Li's replacement in Monday's event, Radwanska, has 12 career titles, including wins this season in Auckland and Sydney as well as a quarter-final finish at the Australian Open. On the same night, Hall of Famers John McEnroe and Ivan Lendl will renew their historic rivalry. Both had memorable match-ups in the 1980s when they had an intense dislike for each other. But today, age has lessened the friction - not that either will want to be a loser.