Spain's Rafael Nadal serves to Argentina's Diego Schwartzman during the Monte-Carlo ATP Masters Series Tournament tennis match, on April 21, 2017 in Monaco. / AFP PHOTO / VALERY HACHE (Photo credit should read VALERY HACHE/AFP/Getty Images)
Spain's Rafael Nadal serves to Argentina's Diego Schwartzman during the Monte-Carlo ATP Masters Series Tournament tennis match, on April 21, 2017 in Monaco. / AFP PHOTO / VALERY HACHE (Photo credit should read VALERY HACHE/AFP/Getty Images)