By Nick Georgandis

TennisNow.com

That tiny shard of glass sitting quietly outside an European restaurant last July sure is causing a lot of trouble.

On Thursday, Australian Open tournament director Craig Tiley announced that former No. 1 and 13-time Grand Slam winner Serena Williams has withdrawn from the field of the event which will be held in Melbourne Jan. 17-23, 2011.

It will be the second straight major that Williams has missed since injuring her right foot just after winning Wimbledon in early July. Williams played off the injury initially, believing she would only miss her World Team Tennis commitment.

But then she withdrew from the US Open Series, the Open itself, a number of tournaments this fall, the WTA Championships and eventually the Fed Cup.

Last week, she announced she would miss the Hopman Cup, and was seen on crutches attending a Miami Dolphins game, and still wearing the large boot that encapsulates her foot and leg up to the calf at a Miami Heat game.

Williams has won the Australian Open five times in her career, including in 2010 when she defeated Justine Henin. The announcement means she also will miss the Sydney Open in early January, an event she reached the finals of a year ago.

Failing to defend those 320 points plus the 2,000 she garnered in Melbourne a year ago means that Williams will likely drop out of the Top 10 a few polls into the new year.