Aug 28, 2017; New York, NY, USA; Steve Johnson of the United States hits a forehand against Nicolas Almagro of Spain (not pictured) on day one of the U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Johnson won 6-4, 7-6(2), 7-6(5). Mandatory Credit: Geoff Burke-USA TODAY Sports

Aug 28, 2017; New York, NY, USA; Nicolas Almagro of Spain reaches for a forehand against Steve Johnson of the United States (not pictured) on day one of the U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Johnson won 6-4, 7-6(2), 7-6(5). Mandatory Credit: Geoff Burke-USA TODAY Sports

Aug 28, 2017; New York, NY, USA; Nicolas Almagro of Spain hits a volley against Steve Johnson of the United States (not pictured) on day one of the U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Johnson won 6-4, 7-6(2), 7-6(5). Mandatory Credit: Geoff Burke-USA TODAY Sports

Aug 28, 2017; New York, NY, USA; Steve Johnson of the United States serves against Nicolas Almagro of Spain (not pictured) on day one of the U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Johnson won 6-4, 7-6(2), 7-6(5). Mandatory Credit: Geoff Burke-USA TODAY Sports

Tennis - ATP - Rome Open - Rafael Nadal of Spain v Nicolas Almagro of Spain - Rome, Italy - 17/5/17 - Nadal returns the ball. REUTERS/Max Rossi

Tennis - ATP - Rome Open - Rafael Nadal of Spain v Nicolas Almagro of Spain - Rome, Italy - 17/5/17 - Nadal returns the ball. REUTERS/Max Rossi

Tennis - ATP - Rome Open - Rafael Nadal of Spain v Nicolas Almagro of Spain - Rome, Italy - 17/5/17 - Nadal returns the ball. REUTERS/Max Rossi

Tennis - ATP - Rome Open - Rafael Nadal of Spain v Nicolas Almagro of Spain - Rome, Italy - 17/5/17 - Nadal serves the ball. REUTERS/Max Rossi

Tennis - ATP - Rome Open - Rafael Nadal of Spain v Nicolas Almagro of Spain - Rome, Italy - 17/5/17 - Nadal serves the ball. REUTERS/Max Rossi

Tennis - ATP - Rome Open - Rafael Nadal of Spain v Nicolas Almagro of Spain - Rome, Italy - 17/5/17 - Nadal returns the ball. REUTERS/Max Rossi

Tennis - ATP - Rome Open - Rafael Nadal of Spain v Nicolas Almagro of Spain - Rome, Italy - 17/5/17- Almagro leaves the court following an injury to his knee. REUTERS/Max Rossi

Tennis - ATP - Rome Open - Rafael Nadal of Spain v Nicolas Almagro of Spain - Rome, Italy - 17/5/17 - Almagro is applied with a bandage following an injury to his knee. REUTERS/Max Rossi

Tennis - ATP - Rome Open - Rafael Nadal of Spain v Nicolas Almagro of Spain - Rome, Italy - 17/5/17 - Almagro reacts following an injury to his knee. REUTERS/Max Rossi

Tennis - ATP - Rome Open - Rafael Nadal of Spain v Nicolas Almagro of Spain - Rome, Italy - 17/5/17 - Almagro is treated by a doctor following an injury to his knee. REUTERS/Max Rossi

Tennis - ATP - Rome Open - Rafael Nadal of Spain v Nicolas Almagro of Spain - Rome, Italy - 17/5/17 - Nadal talks with Almagro as he touches his knee following an injury. REUTERS/Max Rossi

Tennis - ATP - Rome Open - Rafael Nadal of Spain v Nicolas Almagro of Spain - Rome, Italy - 17/5/17 - Nadal talks with Almagro as he touches his knee following an injury. REUTERS/Max Rossi

Tennis - ATP 1000 Masters - Madrid Open - Nicolas Almagro of Spain v Novak Djokovic of Serbia - Madrid, Spain - 10/5/17 - Almagro returns a ball. REUTERS/Paul Hanna

Tennis - ATP 1000 Masters - Madrid Open - Nicolas Almagro of Spain v Novak Djokovic of Serbia - Madrid, Spain - 10/5/17 - Almagro returns a ball. REUTERS/Paul Hanna

Tennis - ATP 1000 Masters - Madrid Open - Nicolas Almagro of Spain v Novak Djokovic of Serbia - Madrid, Spain - 10/5/17 - Almagro reacts after losing a point. REUTERS/Paul Hanna

Tennis - ATP 1000 Masters - Madrid Open - Nicolas Almagro of Spain v Novak Djokovic of Serbia - Madrid, Spain - 10/5/17 - Almagro in action. REUTERS/Paul Hanna

Tennis - ATP 1000 Masters - Madrid Open - Nicolas Almagro of Spain v Novak Djokovic of Serbia - Madrid, Spain - 10/5/17 - Almagro serves a ball. REUTERS/Paul Hanna

Tennis - ATP 1000 Masters - Madrid Open - Nicolas Almagro of Spain v Novak Djokovic of Serbia - Madrid, Spain - 10/5/17 - Djokovic in action. REUTERS/Paul Hanna

Tennis - ATP 1000 Masters - Madrid Open - Nicolas Almagro of Spain v Novak Djokovic of Serbia - Madrid, Spain - 10/5/17 - Djokovic serves a ball. REUTERS/Paul Hanna

Tennis - ATP 1000 Masters - Madrid Open - Nicolas Almagro of Spain v Novak Djokovic of Serbia - Madrid, Spain - 10/5/17 - Djokovic returns a shot. REUTERS/Paul Hanna

Tennis - ATP 1000 Masters - Madrid Open - Nicolas Almagro of Spain v Novak Djokovic of Serbia - Madrid, Spain - 10/5/17 - Djokovic lunges for a ball. REUTERS/Paul Hanna

Tennis - ATP 1000 Masters - Madrid Open - Nicolas Almagro of Spain v Novak Djokovic of Serbia - Madrid, Spain - 10/5/17 - Djokovic lunges for a ball. REUTERS/Paul Hanna

Tennis - ATP 1000 Masters - Madrid Open - Nicolas Almagro of Spain v Novak Djokovic of Serbia - Madrid, Spain - 10/5/17 - Djokovic serves a ball. REUTERS/Paul Hanna

Tennis - ATP 1000 Masters - Madrid Open - Nicolas Almagro of Spain v Novak Djokovic of Serbia - Madrid, Spain - 10/5/17 - Djokovic in action. REUTERS/Paul Hanna

Tennis - ATP 1000 Masters - Madrid Open - Nicolas Almagro of Spain v Novak Djokovic of Serbia - Madrid, Spain - 10/5/17 - Djokovic returns a ball. REUTERS/Paul Hanna

Tennis - ATP 1000 Masters - Madrid Open - Nicolas Almagro of Spain v Novak Djokovic of Serbia - Madrid, Spain - 10/5/17 - Djokovic returns a ball. REUTERS/Paul Hanna

Tennis - Monte Carlo Masters - Monaco, 18/04/2017. Nicolas Almagro of Spain plays a shot to David Goffin of Belgium. REUTERS/Eric Gaillard

Tennis - Monte Carlo Masters - Monaco, 18/04/2017. Nicolas Almagro of Spain plays a shot to David Goffin of Belgium. REUTERS/Eric Gaillard

Tennis - Monte Carlo Masters - Monaco, 18/04/2017. David Goffin of Belgium plays a shot to Nicolas Almagro of Spain. REUTERS/Eric Gaillard

Tennis - Monte Carlo Masters - Monaco, 18/04/2017. David Goffin of Belgium plays a shot to Nicolas Almagro of Spain. REUTERS/Eric Gaillard

Tennis - Qatar Open - Men's Singles - Andy Murray of Britain v Nicolas Almagro of Spain - Doha, Qatar - 5/1/2017 -Murray waves after winning. REUTERS/Ibraheem Al Omari

Tennis - Qatar Open - Men's Singles - Andy Murray of Britain v Nicolas Almagro of Spain - Doha, Qatar - 5/1/2017 -Murray waves after winning. REUTERS/Ibraheem Al Omari

Tennis - Qatar Open - Men's Singles - Andy Murray of Britain v Nicolas Almagro of Spain - Doha, Qatar - 5/1/2017 - Murray in action. REUTERS/Ibraheem Al Omari

Tennis - Qatar Open - Men's Singles - Andy Murray of Britain v Nicolas Almagro of Spain - Doha, Qatar - 5/1/2017 - Almagro serves the ball. REUTERS/Ibraheem Al Omari

Tennis - Qatar Open - Men's Singles - Andy Murray of Britain v Nicolas Almagro of Spain - Doha, Qatar - 5/1/2017 -Almagro in action. REUTERS/Ibraheem Al Omari

Tennis - Qatar Open - Men's Singles - Andy Murray of Britain v Nicolas Almagro of Spain - Doha, Qatar - 5/1/2017 - Murray reacts. REUTERS/Ibraheem Al Omari

Tennis - Qatar Open - Men's Singles - Andy Murray of Britain v Nicolas Almagro of Spain - Doha, Qatar - 5/1/2017 - Almagro in action. REUTERS/Ibraheem Al Omari

Tennis - Qatar Open - Men's Singles - Andy Murray of Britain v Nicolas Almagro of Spain - Doha, Qatar - 5/1/2017 - Murray in action. REUTERS/Ibraheem Al Omari

Tennis - Qatar Open - Men's Singles - Andy Murray of Britain v Nicolas Almagro of Spain - Doha, Qatar - 5/1/2017 - Murray serves the ball. REUTERS/Ibraheem Al Omari

Tennis - Qatar Open - Men's Singles - Andy Murray of Britain v Nicolas Almagro of Spain - Doha, Qatar - 5/1/2017 -Murray in action. REUTERS/Ibraheem Al Omari

Tennis - Qatar Open - Men's Singles - Andy Murray of Britain v Nicolas Almagro of Spain - Doha, Qatar - 5/1/2017 -Almagro in action. REUTERS/Ibraheem Al Omari

Tennis - Qatar Open - Men's Singles - Andy Murray of Britain v Nicolas Almagro of Spain - Doha, Qatar - 5/1/2017 - Murray in action. REUTERS/Ibraheem Al Omari

Tennis - Shanghai Masters tennis tournament - Shanghai, China - 10/10/16. Mikhail Youzhny of Russia plays against Nicolas Almagro of Spain. REUTERS/Aly Song

Tennis - Shanghai Masters tennis tournament - Shanghai, China - 10/10/16. Mikhail Youzhny of Russia plays against Nicolas Almagro of Spain. REUTERS/Aly Song

Tennis - Shanghai Masters tennis tournament - Shanghai, China - 10/10/16. Nicolas Almagro of Spain plays against Mikhail Youzhny of Russia. REUTERS/Aly Song

Tennis - Shanghai Masters tennis tournament - Shanghai, China - 10/10/16. Mikhail Youzhny of Russia plays against Nicolas Almagro of Spain. REUTERS/Aly Song

Tennis - Shanghai Masters tennis tournament - Shanghai, China - 10/10/16. Mikhail Youzhny of Russia plays against Nicolas Almagro of Spain. REUTERS/Aly Song

Sep 2, 2016; New York, NY, USA; Nicolas Almagro of Spain serves against Gael Monfils of France (not pictured) on day five of the 2016 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Monfils won 6-4, 6-2, 6-4. Mandatory Credit: Geoff Burke-USA TODAY Sports

Sep 2, 2016; New York, NY, USA; Nicolas Almagro of Spain reaches for a forehand against Gael Monfils of France (not pictured) on day five of the 2016 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Monfils won 6-4, 6-2, 6-4. Mandatory Credit: Geoff Burke-USA TODAY Sports

Sep 2, 2016; New York, NY, USA; Gael Monfils of France (L) shakes hands with Nicolas Almagro of Spain (R) after their match on day five of the 2016 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Monfils won 6-4, 6-2, 6-4. Mandatory Credit: Geoff Burke-USA TODAY Sports

Sep 2, 2016; New York, NY, USA; Gael Monfils of France gestures towards his player's box after his match against Nicolas Almagro of Spain (not pictured) on day five of the 2016 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Monfils won 6-4, 6-2, 6-4. Mandatory Credit: Geoff Burke-USA TODAY Sports

Sep 2, 2016; New York, NY, USA; Gael Monfils of France hits a volley against Nicolas Almagro of Spain (not pictured) on day five of the 2016 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Monfils won 6-4, 6-2, 6-4. Mandatory Credit: Geoff Burke-USA TODAY Sports

Sep 2, 2016; New York, NY, USA; Gael Monfils of France hits a forehand against Nicolas Almagro of Spain (not pictured) on day five of the 2016 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Monfils won 6-4, 6-2, 6-4. Mandatory Credit: Geoff Burke-USA TODAY Sports

Sep 2, 2016; New York, NY, USA; Gael Monfils of France (R) jokes with Nicolas Almagro of Spain (L) during their match on day five of the 2016 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Monfils won 6-4, 6-2, 6-4. Mandatory Credit: Geoff Burke-USA TODAY Sports

Sep 2, 2016; New York, NY, USA; Gael Monfils of France serves against Nicolas Almagro of Spain (not pictured) on day five of the 2016 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Monfils won 6-4, 6-2, 6-4. Mandatory Credit: Geoff Burke-USA TODAY Sports

Aug 31, 2016; New York, NY, USA; Nicolas Almagro of Spain returns a shot during his match against Pablo Cuevas of Uruguay on day three of the 2016 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Jerry Lai-USA TODAY Sports