Serena Williams withdraws from Brisbane after ankle sprain.

Serena Williams withdrew from the Brisbane International on Wednesday after suffering an ankle sprain during a match.

The 30-year-old American was serving for the match against Bojana Jovanski when she fell hard to the court during a rally. She was attended to by trainers and took a brief break, then returned to close out the match, winning 6-2, 6-4.

Following the victory, Serena was optimistic that she may be able to play on Thursday. But in a statement issued a few hours later, she announced her withdrawal.

"I have been to the hospital and it has been confirmed that I have a left ankle sprain that I probably shouldn't play on," Serena wrote in a statement. "I'm going to take a couple of days off — not too many — and see how I feel. I'm still hopeful of playing the Australian Open."

The 13-time Grand Slam champion may have herself to blame for the injury. She removed the ankle brace she usually wears earlier in the match because it was causing her pain.

Serena has until the start of the Australian Open on Jan. 16 to recover. She has won the tournament four times in her career and would enter as a favorite to earn her fifth title.

Her appearance in Brisbane was her first tournament since losing the US Open final to Sam Stosur last September.