It was at that event where Sharapova 's test turned up positive .
The ITF announced that the suspension would be backdated to Jan. 26 , which invalidates Sharapova 's quarterfinals performance in January 's Australian Open .
ITF was at that event where Sharapova 's test turned up positive .
The ITF announced that the suspension would be backdated to Jan. 26 , which invalidates Sharapova 's quarterfinals performance in January 's Australian Open .