World number two Maria Sharapova has said that she expects a tough battle against Li Na in their Australian Open semi-final in Melbourne.
The Russian has dropped just nine games on her way to the last four, and holds a winning 8-4 record over the Chinese sixth seed.
Sharapova said that Li, who claimed her seventh WTA title at the Shenzhen Open at the start of the month, has improved her game considerably over the last year.
"I've beaten her the last few times that we've played, but they've always been really good matches, really tough matches," said Sharapova. "I certainly expect it in the next one.
"She's had a great start to the year and is playing really well.
"She was the most-improved player towards the end of last year as well, so that will be hopefully a high-quality semi."
The 25-year-old holds a winning 8-4 record over Li.