LONDON, ENGLAND - NOVEMBER 10: Alexander Zverev talks with coach Ivan Lendl during a practice session prior to the Nitto ATP Finals at The O2 Arena on November 10, 2018 in London, England. (Photo by Clive Brunskill/Getty Images)
LONDON, ENGLAND - NOVEMBER 10: Alexander Zverev talks with coach Ivan Lendl during a practice session prior to the Nitto ATP Finals at The O2 Arena on November 10, 2018 in London, England. (Photo by Clive Brunskill/Getty Images)