Dubai: Top seeds Serena Williams and Angelique Kerber have withdrawn from the WTA Tennis Championships, organisers announced on Saturday.
"We regret to announce that Serena Williams and Angelique Kerber have withdrawn due to illness and injury," the Dubai Duty Free Tennis Championships wrote on their official Twitter account ahead of the draw.
The news is a double blow for organisers with Williams and Kerber, the world`s top two players, seeded number one and two respectively.
The 28-year-old German shocked Williams, 34, in the Australian Open final last month to win her first Grand Slam title.
Williams, whose pullout was her third in four years on short notice in Dubai, said: "I`m disappointed to have to withdraw from the Dubai Tennis Championships.
"I have come down with the flu and I am not at 100 percent, so I need to take this time to recuperate."
Williams last appeared at the tournament in a semi-final two years ago, losing to Alize Cornet.
Kerber said: "I am very sad to announce that I have to withdraw from this great tournament in Dubai due to an injury of my right upper thigh.
"I wish all of you a lot of fun and great week of tennis. Looking forward to being on court again as soon as possible."
In addition to Williams and Kerber, other absentees include 2012 champion Agnieszka Radwanska, Switzerland`s Roland Garros semi-finalist Timea Bacsinszky, Dane Caroline Wozniacki, the winner in 2011, plus China`s Peng Shuai and injured Frenchwoman Cornet.
Defending champion Simona Halep of Romania is now the top seed in the tournament which starts on Monday with world number five Garbine Muguruza of Spain moving up to second seed.