Serena Williams will no longer be the world's top ranked women's player after announcing that she will not be a part of the BNP Paribas Open in Indian Wells.

Williams last played in the 2017 Australian Open where she defeated her sister Venus in the final, overtaking Steffi Graf for most Grand Slam singles titles in the Open era with 23 and reclaiming her world number one spot in the process.

However, a left knee injury has forced the 35-year-old to withdraw from the BNP Paribas Open that commences 8 March, with Williams also revealing that she will be miss the Miami Open which takes place on 20 March.

"Sadly, I have to withdraw from the BNP Paribas Open in Indian Wells and the Miami Open,'' she said as quoted on The Guardian. "I have not been able to train due to my knees and am disappointed I cannot be there."

"I will keep moving forward and continue to be positive. I look forward to being back as soon as I can.''

As a result of the withdrawal, Williams – who won at Indian Wells in 1999 and 2001 – will now lose her world number one ranking as she needed to reach at least the semi-finals to retain her place.

US Open champion and world number two Angelique Kerber – who lost her top spot following the Australian Open – will now reclaim her world number one rank regardless of her performances in Indian Wells due to the finalist points Williams will be surrendering.