Angelique Kerber of Germany returns the ball to Camila Giorgi of Italy during their first round match of the Brisbane International Tennis Tournament in Brisbane, Australia, 04 January 2016. EPA/DAVE HUNT

France’s Kenny De Schepper returns the ball to Britain’s Andy Murray during their men’s singles match between Great Britain and France in session 4 of the Hopman Cup tennis tournament at the Perth Arena in Perth, Australia, 04 January 2016. EPA/TONY MCDONOUGH

Jelena Jankovic of Serbia returns to Roberta Vinci of Italy on day 2 of the Brisbane International Tennis Tournament in Brisbane, Australia 04 January 2016. EPA/DAVE HUNT

Britain’s Andy Murray returns the ball to France’s Kenny De Schepper during their men’s singles match between Great Britain and France in session 4 of the Hopman Cup tennis tournament at the Perth Arena in Perth, Australia, 04 January 2016. EPA/TONY MCDONOUGH

Alexander Zverev for Germany returns a ball to Nick Kyrgios for Australia Green (not pictured) during the Hopman Cup men’s singles match at the Perth Arena, Australia, 03 January 2016. Australia won the match. EPA/TONY MCDONOUGH

Victoria Azarenka of Belarus celebrates after defeating Elena Vesnina of Russia in their first round match of the Brisbane International Tennis Tournament in Brisbane, Australia, 04 January 2016. EPA/DAVE HUNT