Serena Williams is set to make her comeback from a knee injury at the Madrid Open in May. 

Williams has not played competitively since winning an Open Era-record 23rd grand slam title at the Australian Open in January.

The legendary American withdrew from the BNP Paribas Open at Indian Wells this month, revealing that she had not been able to train due to a problem with her left knee.

  This is the look I have the moment before walking on the court for a championship match. A post shared by Serena Williams (@serenawilliams) on Mar 28, 2017 at 7:07am PDT

Williams has been selective over which tournaments she has entered in order to give herself every chance of challenging for further major titles, but was on Tuesday included in the entry list for the Madrid Open.

The world number two's appearance on the clay in the Spanish capital, fitness-permitting, will give her an opportunity to gain some momentum ahead of the French Open.

Maria Sharapova, who will make her return from a doping ban in Stuttgart next month, has also been invited to feature in Madrid.