Australia’s player Nick Kyrgios in action against Spain’s Albert Ramos Vinolas (not pictured) during the Estoril Open 2015 first round, in Estoril Tennis Club, outskirts of Lisbon, Portugal, 29 April 2015. EPA/MARIO CRUZ

Andy Murray of Great Britain in action during his first round doubles match against Raven Klaasen of South Africa and Lukas Rosol of the Czech Republic at the ATP Tennis Tournament in Munich, Germany, 29 April 2015. EPA/MARC MUELLER

Roger Federer of Switzerland returns the ball to Jarkko Nieminen during the first round match of the TEB BNP Paribas Istanbul Open tennis Tournament in Istanbul, Turkey, 29 April 2015. EPA/TOLGA BOZOGLU

Spain’s player Feliciano Lopez in action against Netherland’s Robin Haase (not pictured) during the Estoril Open 2015 second round, in Estoril Tennis Club, outskirts of Lisbon, Portugal, 29 April 2015. EPA/MARIO CRUZ

Fabio Fognini of Italy returns the ball to Trinker of Austria during the first round match of the ATP tennis tournament in Munich, Germany, 28 April 2015. EPA/MARC MUELLER