June 20, 2018 - London, England, United Kingdom - Gilles Muller (LUX) in action. during the Fever-Tree Championships 2nd Round match between Frances Tiafoe (USA) and Leonardo Mayer(ARG) at The Queen's Club, London, on June 20, 2018 (Credit Image: © Kieran Galvin/NurPhoto via ZUMA Press)
June 20, 2018 - London, England, United Kingdom - Gilles Muller (LUX) in action .during Fever-Tree Championships 2nd Round match between Frances Tiafoe (USA) against Leonardo Mayer(ARG) at The Queen's Club, London, on 20 June 2018  (Credit Image: © Kieran Galvin/NurPhoto via ZUMA Press)