BNL D’Italia 2017

ROME, ITALY – MAY 19: Rafael Nadal of Spain slips during the men’s quarter-final match against Dominic Thiem of Austria on Day Six of the Internazionali BNL d’Italia 2017 at Foro Italico on May 19, 2017 in Rome, Italy. (Photo by Michael Steele/Getty Images)

Rafael Nadal of Spain serves against Nicolas Almagro of Spain during their match at the ATP Tennis Open tournament on May 17, 2017 at the Foro Italico in Rome. Rafael Nadal advanced to the Rome Masters third round on Wednesday as fellow Spaniard Nicolas Almagro was forced to retire with a left knee injury. Almagro, a three-time French Open quarter-finalist – he lost all three to Nadal – was unable to continue after 24 minutes while trailing his compatriot 3-0 in the first set. / AFP PHOTO / TIZIANA FABI (Photo credit should read TIZIANA FABI/AFP/Getty Images)

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

Rafael Nadal of Spain hits a return to Nicolas Almagro of Spain during their match at the ATP Tennis Open tournament on May 17, 2017 at the Foro Italico in Rome. Rafael Nadal advanced to the Rome Masters third round on Wednesday as fellow Spaniard Nicolas Almagro was forced to retire with a left knee injury. Almagro, a three-time French Open quarter-finalist – he lost all three to Nadal – was unable to continue after 24 minutes while trailing his compatriot 3-0 in the first set. / AFP PHOTO / TIZIANA FABI (Photo credit should read TIZIANA FABI/AFP/Getty Images)

Rafael Nadal of Spain (R) talks with Nicolas Almagro of Spain forced to abandoned after an injury during their match at the ATP Tennis Open tournament on May 17, 2017 at the Foro Italico in Rome. / AFP PHOTO / TIZIANA FABI (Photo credit should read TIZIANA FABI/AFP/Getty Images)

Rafael Nadal of Spain (L) talks with Nicolas Almagro of Spain forced to abandoned after an injury during their match at the ATP Tennis Open tournament on May 17, 2017 at the Foro Italico in Rome. / AFP PHOTO / TIZIANA FABI (Photo credit should read TIZIANA FABI/AFP/Getty Images)

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

Rafael Nadal of Spain (R) helps Nicolas Almagro of Spain forced to abandoned after an injury during their match at the ATP Tennis Open tournament on May 17, 2017 at the Foro Italico in Rome. / AFP PHOTO / TIZIANA FABI (Photo credit should read TIZIANA FABI/AFP/Getty Images)

ROME, ITALY – MAY 17: Rafael Nadal of Spain walks towards an injured Nicolas Almagro of Spain who retired whilst losing 0-3 in the opening set on Day Four of The Internazionali BNL d’Italia 2017 at the Foro Italico on May 17, 2017 in Rome, Italy. (Photo by Michael Steele/Getty Images)

on Day Four of The Internazionali BNL d’Italia 2017 at the Foro Italico on May 17, 2017 in Rome, Italy.

ROME, ITALY – MAY 17: Rafael Nadal of Spain in action during his second round match against Nicolas Almagro of Spain on Day Four of The Internazionali BNL d’Italia 2017 at the Foro Italico on May 17, 2017 in Rome, Italy. (Photo by Michael Steele/Getty Images)

ROME, ITALY – MAY 17: Nicolas Almagro (C) of Spain is helped off court by Rafael Nadal (R) of Spain and umpire Carlos Bernardes (L) after retiring at 0-3 in the opening set on Day Four of The Internazionali BNL d’Italia 2017 at the Foro Italico on May 17, 2017 in Rome, Italy. (Photo by Michael Steele/Getty Images)