Williams also reached the 2008 Wimbledon final before finishing second to her older sister Venus Williams in straight sets.
After winning the Australian Open in January, Williams withdrew injured in the Paris Open semifinals. Then Williams lost to Venus Williams in the Dubai semifinals.
Earlier this month, Williams was able to reach the final of the Sony Ericsson Open at Miami. However she struggled again with a leg injury which prevented her from performing at any high level.
Finally last week Williams lost her opening match at Marbella, Spain 6-4, 3-6, 6-1 to the 95th ranked Klara Zakopalova of the Czech Republic before she withdrew from this week's Family Circle Cup at Charleston, South Carolina citing the leg injury.
“I am unable to compete this year at the Family Circle Cup as I need to give my leg injury time to heal,” Williams said.
And although Williams holds two grand slam titles to none for Safina, Williams started 2008 with a 19-1 WTA Tour record after winning Charleston last year for her third tittle win in a row after also taking titles in Bangalore and Miami.
The combination of Williams' failure to defend those points plus Safina's ability to win several more matches in early 2009 than she did in early 2008 will result in the top ranking next week for Safina.
And while Safina was impressive last year while winning titles in Berlin, Los Angeles, Montreal and Tokyo, the Russian has so far failed to win a title this year and was steamrolled by Williams in the Melbourne final 6-0, 6-3.
Williams leads Safina head to head 6-1 with the Russian's only win a 2-6, 6-1, 7-6(7-5) struggle in last year's Berlin quarterfinals. The victory would snap a Williams 17 match winning streak.
Told several weeks ago in Miami that Safina could replace her at the top, Williams shrugged off the possible rankings change.
“It will be kind of weird to be No. 2,” Williams said, “because I think the girl that would take over
would be like -- lost early here and hasn't really, whatever.”
“So it's like whatever. I don't really care. My whole goal in life isn't to be No. 1. Yeah, I want to be No. 1, but I feel better about winning Australia or US Open or winning the French Open or anything like that. I think I feel better with that.”