Serena facing triple threat

Serena Williams' status as the world No 1 is under serious threat going into the Australian Open this week, with three players able to unseat her as the top ranked female player.

The American held on to the top ranking for the entire 2014 season and if she makes the final at Melbourne Park nobody can take it away from her.

But if the 33-year-old doesn't, it could be claimed by either Maria Sharapova, Simona Halep or Petra Kvitova.