Indian Wells, USA, 15 March 2013 | tennis.com.au

Sam Stosur has withdrawn from her quarterfinal match at the BNP Paribas Open due to a right calf injury.

The Australian No.7 seed was due to take on fourth seed Angelique Kerber in the first match of Thursday’s schedule on Stadium 1.

“I hurt my right calf muscle in the last game of my match against Mona Barthel when I was serving for the match,” Stosur revealed, “so I don’t know if you can get any more unlucky than that.

“I think we only played another four points in that match. I felt something go in my calf and it was hurting a fair bit. Yesterday I took the day off practice and only did treatment, probably iced it about 10 times. This morning I thought I would give it a shot, and tried to go out and warm up, and after about five minutes I knew that there was no chance I could play unfortunately.”

The injury puts a cloud over her participation at next week’s Sony Open in Miami.

“Today I’ll talk to the physios and the doctors and work out a good plan for how many days off I need to take off and go from there,” Stosur said.

“It’s all a bit up in the air at the moment because I’ve never been through this type of injury before, so it’s a matter of wait and see, talking to the people who know, and reassessing each day.”

In the semifinals, Kerber will face Caroline Wozniacki, who, in a disastrous day for Indian Wells tournament organisers, also progressed via an opponent’s withdrawal.

Wozniacki was due to face top seed Victoria Azarenka, who has recently been struggling with a right ankle injury.

The Belarusian decided that the injury was too much to overcome, giving Wozniacki a free pass into the final four.

For Stosur, the injury came just as she was starting to enjoy some consistent form, and as she was on the brink of reaching her first WTA semifinal since Moscow in October last year.

“It’s really disappointing. I had a bit of a rough start to the year and I feel like now my tennis has really picked up, and I’ve been playing really quite well these last few days,” she lamented.

“I love the conditions here at the BNP Paribas Open and I love playing in front of this crowd, so to have to pull out without even being able to get on court is probably as bad as it gets. I think this is only the second time I’ve ever pulled out of a match in my career, and unfortunately there isn’t anything I can do about it.”