Simona Halep is facing a spell on the sidelines after suffering a recurrence of the foot injury which hampered her at the Australian Open last month.
The world number two defeated Catherine Bellis 6-0 6-4 at the Qatar Open, only to immediately withdraw from her semi-final with Garbine Muguruza as she confirmed more fitness issues.
She told reporters: "I withdraw because I cannot play anymore and it's going to be dangerous if I force it.
I withdraw because I cannot play anymore and it's going to be dangerous if I force it.Simona Halep
"Today it was worse and that's why I took this decision. It's not easy, but I talked to my doctor and he said that I didn't have enough time to recover.
"The MRI shows that I have fluid and also tendinitis at the fourth toe, so I have just to take care of it and think about my health first."
Halep battled her way all the way to the final of the Australian Open in Melbourne, only to be denied a first Grand Slam title in a gruelling three-setter with Caroline Wozniacki.
Meanwhile, Wozniacki, who claimed her first major crown in the process, faces Petra Kvitova in the last four at the Qatar Open, having outlasted Angelique Kerber 7-6 1-6 6-3 to reach the semi-finals.
Two-time Wimbledon champion Kvitova holds a 7-5 winning record in 12 previous matches with world number one Wozniacki and has won all of their last three meetings.
Kvitova is 1/1 to defeat 2017 Qatar Open runner-up Wozniacki and is 7/2 to do so in three sets, with Wozniacki priced at 3/1 to earn victory in a three-setter.
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