Roger Federer of Switzerland returns to Samuel Groth of Australia in their third round match during the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 04 July 2015. EPA/GERRY PENNY

Roger Federer of Switzerland returns to Samuel Groth of Australia in their third round match during the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 04 July 2015. EPA/GERRY PENNY

Roger Federer of Switzerland serves to Samuel Groth of Australia in their third round match during the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 04 July 2015. EPA/GERRY PENNY

Roger Federer of Switzerland celebrates his win over Samuel Groth of Australia in their third round match during the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 04 July 2015. EPA/GERRY PENNY

Roger Federer of Switzerland returns to Samuel Groth of Australia in their third round match during the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 04 July 2015. EPA/GERRY PENNY

Roger Federer of Switzerland returns to Samuel Groth of Australia in their third round match during the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 04 July 2015. EPA/GERRY PENNY