A second operation on Serena Williams' foot has forced her to withdraw from the Australian Open, the first tournament of 2011 and the two-time defending champion.
The Grand Slam is William's second consecutive Slam she has withdrawn from after she sustained a foot injury in July. Then, Williams stepped on a piece of glass at a restaurant, causing her to have surgery.
The 29-year-old American also pulled out of Hopman Cup international mixed teams competition in Perth.
Williams has only played one tournament from July, and her loss of 2,000 ranking points might cause her to drop from the top 10.
She is currently ranked No. 4.