(FILE PHOTO) Rafael Nadal,Grand Slam champion, will retire from tennis at the end of this season. MELBOURNE, AUSTRALIA - JANUARY 21: Rafael Nadal of Spain waves to the crowd after winning his Men's Singles first round match against Hugo Dellien of Bolivia on day two of the 2020 Australian Open at Melbourne Park on January 21, 2020 in Melbourne, Australia. (Photo by Cameron Spencer/Getty Images)