Former world number one Victoria Azarenka withdrew from the WTA Madrid Open on Wednesday (4th May) due to a back injury.

SOUNDBITE: (English) Victoria Azarenka, Former world number one:

"My theory is that it was wrong, a little bit of movement and as I said when it's really cold weather and you sweat a little bit, it's very easy to get those tweaks. You know, especially the match before that, I don't think it helped a lot so ...But it is what it is."

SOUNDBITE: (English) Victoria Azarenka, Former world number one:

"Well, I'm not going to sit here and beat myself that I got hurt, it's just sports and I just need to stay positive and make sure that I do everything right to be able to move forward. My preparation is delayed a little bit with the matches but going on the court, playing what I did in the last match also doesn't help my improvement. As I said, beginning of the year, throughout the year, it's all about improvement and I'm going to make those choices for that."

SOUNDBITE: (English) Victoria Azarenka, Former world number one:

"It was better, it felt a little easier yesterday and before my hitting today but I was serving in my match very slowly and today in the warm-up it was not really possible. So I tried to be ready but I think just one day of rest is not enough."