The Hopman Cup mixed team event suffered a double blow on Thursday when American Venus Williams and the Germany team pulled out of the tournament in Perth, Australia.

Williams, the former world number one and highest profile player due to take part in the event starting on December 30, and German Nicolas Kiefer both have wrist injuries.

The Germans, who were only called up last month in place of South Korea, were forced to drop out of the tournament and their place will be taken by France.

"Kiefer and Williams have both had recurring problems with their wrists and after long rehabilitations were not able to perform well enough to make the trip to Perth," Hopman Cup organisers said in a statement.

Teenager Tatiana Golovin, a U.S. Open quarter-finalist this year, and Jerome Haehnel will represent France, with Ashley Harkleroad replacing Williams alongside Mardy Fish in the American team.

France and the U.S. are in Group A along with Australia and Russia. Group B consists of India, the Czech Republic, Croatia and Spain.