A knee injury will keep Chinese tennis star Li Na out of next month’s US Open.

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Na injured her knee in March and has not been able to get the strength back to play at a high level, according to the AP.

In a post on her Facebook page, Na told her fans that she would also be withdrawing from the Women’s Tennis Association tournaments in Montreal and Cincinnati.

“My medical team has advised me that I need to take some time off to rest my knee so it heels. I look forward to getting back on the court this fall in Wuhan and Beijing.”

Na becomes that second big name tennis player to announce an injury in that past two days. Rafael Nadal announced he would be missing two events leading up to the US Open, but hopes to be able to play at the Open.

Na is a two-time major champion. She won her first title in 2011 at the French Open and in Januar, she won the Australian Open.

According to Sports Illustrated, Na is the number two ranked played in the world.