Li Na will sit out next month's US Open with a knee injury, the two-time Grand Slam champion announced on Facebook.
"I wanted to let all of my great fans know that unfortunately I am going to have to withdraw from the upcoming WTA events in Montréal and Cincinnati, as well as the US Open," Li wrote.
"Since March, I have been struggling with my knee and it is just not where I need it to be in order to play at the highest level. My medical team has advised me that I need to take some time off to rest my knee so it heals. I look forward to getting back on the court this fall in Wuhan and Beijing."
Li will also miss the Rogers Cup and the Western & Southern Open in addition to the US Open.
Currently the No. 2 player in the world, Li won the Australian Open in January and the French in 2011. The hasn't missed a major since 2009.