Serena will be joined in the traditional pre-Wimbledon warm-up tournament by her older sister Venus , who is also returning to action after an extended injury layoff . Roger Federer to return to competitive tennis at Halle tournament . Williams has been sidelined for Sunday through injury and illness . Serena Williams 's sister Venus also returns to action in same tournament . Serena Williams pulls out of grass court tournament in Halle .
Roger Federer to return to competitive tennis at Halle tournament . Williams has been sidelined for Sunday through injury and illness . Serena Williams 's sister Venus also returns to action in same tournament . Serena Williams pulls out of grass court tournament in Halle .