LONDON, ENGLAND - NOVEMBER 16: Novak Djokovic of Serbia hits a forehand against Diego Schwartzman of Argentina during Day 2 of the Nitto ATP World Tour Finals at The O2 Arena on November 16, 2020 in London, England. (Photo by TPN/Getty Images)
LONDON, ENGLAND - NOVEMBER 16: Novak Djokovic of Serbia hits a forehand against Diego Schwartzman of Argentina during Day 2 of the Nitto ATP World Tour Finals at The O2 Arena on November 16, 2020 in London, England. (Photo by TPN/Getty Images)