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

Tennis - Monte Carlo Masters - Monaco, 11/04/2016. Richard Gasquet of France serves to Nicolas Almagro of Spain. REUTERS/Eric Gaillard

Tennis - Monte Carlo Masters - Monaco, 11/04/2016. Richard Gasquet of France serves to Nicolas Almagro of Spain. REUTERS/Eric Gaillard

Tennis - Monte Carlo Masters - Monaco, 11/04/2016. Richard Gasquet of France serves to Nicolas Almagro of Spain. REUTERS/Eric Gaillard

Tennis - Monte Carlo Masters - Monaco, 11/04/2016. Nicolas Almagro of Spain casts his shadow on the court during his match against Richard Gasquet of France. REUTERS/Eric Gaillard

Austria's Dominic Thiem holds up a trophy after defeating Spain's Nicolas Almagro (R) in men's singles final at the ATP Argentina Open tennis tournament in Buenos Aires, February 14, 2016. REUTERS/Enrique Marcarian

Austria's Dominic Thiem celebrates after defeating Spain's Nicolas Almagro in men's singles final at the ATP Argentina Open tennis tournament in Buenos Aires, February 14, 2016. REUTERS/Enrique Marcarian

Austria's Dominic Thiem celebrates after defeating Spain's Nicolas Almagro in men's singles final at the ATP Argentina Open tennis tournament in Buenos Aires, February 14, 2016. REUTERS/Enrique Marcarian

Austria's Dominic Thiem celebrates after defeating Spain's Nicolas Almagro in men's singles final at the ATP Argentina Open tennis tournament in Buenos Aires, February 14, 2016. REUTERS/Enrique Marcarian

Austria's Dominic Thiem celebrates after defeating Spain's Nicolas Almagro in men's singles final at the ATP Argentina Open tennis tournament in Buenos Aires, February 14, 2016. REUTERS/Enrique Marcarian

Austria's Dominic Thiem holds up a trophy after defeating Spain's Nicolas Almagro (R) in men's singles match at the ATP Argentina Open tennis tournament in Buenos Aires, February 14, 2016. REUTERS/Enrique Marcarian

Austria's Dominic Thiem holds a trophy after defeating Spain's Nicolas Almagro in men's singles match at the ATP Argentina Open tennis tournament in Buenos Aires, February 14, 2016. REUTERS/Enrique Marcarian

Spain's Nicolas Almagro plays a shot during his men's singles final match against Austria's Dominic Thiem at the ATP Argentina Open tennis tournament in Buenos Aires, February 14, 2016. REUTERS/Enrique Marcarian

Spain's Nicolas Almagro plays a shot during his men's singles final match against Austria's Dominic Thiem at the ATP Argentina Open tennis tournament in Buenos Aires, February 14, 2016. REUTERS/Enrique Marcarian