Marin Cilic from Croatia serves against David Goffin from Belgium during their quarterfinal match at the BNP Paribas Open tennis tournament in Indian Wells, California, USA, 17 March 2016. EPA/MIKE NELSON

Magdalena Rybarikova from Slovakia in action against Victoria Azarenka from Belarus during their quarterfinal match at the BNP Paribas Open tennis tournament in Indian Wells, California, USA, 17 March 2016. EPA/MIKE NELSON

Gael Monfils from France serves against Milos Raonic from Canada during their quarterfinal match at the BNP Paribas Open tennis tournament in Indian Wells, California, USA, 17 March 2016. EPA/MIKE NELSON

Milos Raonic from Canada in action against Gael Monfils from France during their quarterfinal match at the BNP Paribas Open tennis tournament in Indian Wells, California, USA, 17 March 2016. EPA/MIKE NELSON

Rafael Nadal from Spain in action against Kei Nishhikori from Japan during their quarter final match at the BNP Paribas Open tennis tournament in Indian Wells, California, USA, 18 March 2016. EPA/MIKE NELSON