Νέα Υόρκη-22 Αυγούστου 2019: πρωταθλητής του Γκραντ Σλαμ 20 φορές τον Ρότζερ Φέντερερ της Ελβετίας πρακτικές για το 2019 μας Open στο εθνικό κέντρο τένις Μπίλυ Ζαν Κινγκ - Φωτογραφίες & Εικόνες Αρχείου

NEW YORK - AUGUST 22, 2019: 20-time Grand Slam champion Roger Federer of Switzerland practices for the 2019 US Open at Billie Jean King National Tennis Center

NEW YORK - AUGUST 22, 2019: 20-time Grand Slam champion Roger Federer of Switzerland practices for the 2019 US Open at Billie Jean King National Tennis Center

NEW YORK - AUGUST 22, 2019: 20-time Grand Slam champion Roger Federer of Switzerland practices for the 2019 US Open at Billie Jean King National Tennis Center

NEW YORK - AUGUST 22, 2019: 20-time Grand Slam champion Roger Federer of Switzerland practices for the 2019 US Open at Billie Jean King National Tennis Center

NEW YORK - AUGUST 22, 2019: 20-time Grand Slam champion Roger Federer of Switzerland practices for the 2019 US Open at Billie Jean King National Tennis Center

NEW YORK - AUGUST 22, 2018: 13-time Grand Slam champion Novak Djokovic of Serbia practices for the 2018 US Open at Billie Jean King National Tennis

FLUSHING, NY - AUGUST 19: Seventeen times Grand Slam champion Roger Federer practices for US Open 2013 at Arthur Ashe Stadium at Billie Jean King National Tennis Center on August 19, 2013 in Flushing, NY

NEW YORK - AUGUST 22, 2019: 20-time Grand Slam champion Roger Federer of Switzerland practices for the 2019 US Open at Billie Jean King National Tennis Center

NEW YORK - AUGUST 27, 2015: Fourteen times Grand Slam Champion Rafael Nadal of Spain practices for US Open 2015 at Billie Jean King National Tennis Center in New York

FLUSHING, NY - AUGUST 29 Professional tennis player Alexandr Dolgopolov from Ukraine practices for US Open 2013 at Billie Jean King National Tennis Center on August 29, 2013 in Flushing, NY

NEW YORK - AUGUST 19: Professional tennis player Tomas Berdych practices for US Open 2014 at Billie Jean King National Tennis Center on August 19 , 2014 in New York

NEW YORK - AUGUST 22, 2019: 20-time Grand Slam champion Roger Federer of Switzerland practices for the 2019 US Open at Billie Jean King National Tennis Center

NEW YORK - AUGUST 22, 2018: 20-time Grand Slam champion Roger Federer of Switzerland practices for the 2018 US Open at Billie Jean King National Tennis Center

NEW YORK - AUGUST 24 Professional tennis player Fabio Fognini from Italy practices for US Open 2013 at Billie Jean King National Tennis Center on August 24, 2013 in New York

FLUSHING, NY - AUGUST 20: Professional tennis player Jerzy Janowicz practices for US Open 2013 at Louis Armstrong Stadium at Billie Jean King National Tennis Center on August 20, 2013 in Flushing, NY

NEW YORK - AUGUST 22, 2017: Nineteen times Grand Slam Champion Roger Federer of Switzerland practices for US Open 2017 at Billie Jean King National Tennis Center in New York

NEW YORK - AUGUST 28, 2017: Professional tennis player Marin Cilic of Croatia in action during his 2017 US Open first round match at Billie Jean King National Tennis Center

FLUSHING, NY - AUGUST 21: Professional tennis player Fernando Verdasco practices for US Open at Louis Armstrong Stadium at Billie Jean King National Tennis Center on August 21, 2012 in Flushing, NY.

NEW YORK - AUGUST 22, 2018: 13-time Grand Slam champion Novak Djokovic of Serbia practices for the 2018 US Open at Billie Jean King National Tennis

DELRAY BEACH, FLORIDA - FEBRUARY 18, 2022: Professional tennis player Sebastian Korda of United States in action during his quarter-final match at the 2022 Delray Beach Open tournament in Florida