Former world number one Caroline Wozniacki has withdrawn from the Qatar Open due to a viral illness.
The 2018 Australian Open champion was due to face Karolina Muchova on Tuesday, but pulled out ahead of the first-round match.
Wozniacki has not played since losing to Maria Sharapova in the third round of the Australian Open last month.
Sam Stosur replaces the Dane, who revealed late last year that she had been diagnosed with rheumatoid arthritis, as a lucky loser.
Wozniacki, a semi-finalist in Doha last year, is set to drop out of the top 10 in the rankings next week.