A court is covered due to rain during the French Open tennis tournament at Roland Garros in Paris, France, 31 May 2016. EPA/IAN LANGSDON

Roberto Bautista Agut of Spain in action against Novak Djokovic of Serbia during their men’s single round of 16 match at the French Open tennis tournament at Roland Garros in Paris, France, 31 May 2016. EPA/YOAN VALAT

Tsvetana Pironkova of Bulgaria in action against Agnieszka Radwanska of Poland during their women’s single round of 16 match at the French Open tennis tournament at Roland Garros in Paris, France, 31 May 2016. EPA/ROBERT GHEMENT

A general view of an almost empty Court 1 as the start of day 9 is delayed due to rain at the French Open tennis tournament at Roland Garros in Paris, France, 31 May 2016. EPA/Caroline Blumberg

David Ferrer of Spain in action against Tomas Berdych of the Czech Republic during their men’s single round of 16 match at the French Open tennis tournament at Roland Garros in Paris, France, 31 May 2016. EPA/ROBERT GHEMENT