Aryna Sabalenka and Iga Swiatek, the world's top two players, have both pulled out of next week's WTA 1000 event in Dubai, tournament organisers announced.
Sabalenka has not played since losing the Australian Open final to Elena Rybakina last month.
"I'm really sorry I have to withdraw from Dubai," said the Belarusian in a statement released by organisers on Friday.
"I have such a special connection with the tournament, the fans and the city. Unfortunately, I am not feeling 100 per cent. But I hope to be back next year and wish the tournament a great event."
Swiatek was in action this week in Doha but failed in her bid for a fourth Qatar Open title, losing to Maria Sakkari in the quarterfinals.
"I am sorry to announce that I will not be playing Dubai this year due to a change of schedule," said the six-time Grand Slam champion.
The first round in Dubai gets under way on Sunday.