Defending champion Simona Halep has withdrawn from next week’s Dubai Tennis Championships with a lower back complaint, organisers of the WTA 1000 tournament said on Thursday.

World No. 3 Halep, who also pulled out of this week’s Qatar Open in Doha, has not played a competitive match since losing in straight sets to Serena Williams in the Australian Open quarterfinals last month.

“Unfortunately I am not feeling 100% in my lower back, and I have made the tough decision to withdraw from the 2021 Dubai Duty Free Tennis Championships,” the 29-year-old Romanian, who also won the Dubai event in 2015, said on social media.

“I have great memories from winning my 20th WTA title after some really tough matches in Dubai last year so I’m disappointed that I won’t be able to defend my title.”

Halep follows world No. 1 Ash Barty, who is recovering from a leg injury, in skipping the Dubai event, which runs from March 7-13.