Perth: World No.1 women's tennis player Serena Williams announced her withdrawal from the Hopman Cup because of an injury in the left knee on Wednesday.


Serena Williams of the US is examined by medical staff for a knee injury before retiring injured against Jamila Wolfe of the Australia Gold team during their sixth session women's singles match on day three of the Hopman Cup tennis tournament in Perth. Pic/AFP

The Hopman Cup is an annual tournament held here between mixed-gender teams held on a country-by-country basis, reports Efe.