Tennis: Novak Djokovic's US Open fate a warning for players to keep emotions in check

September 07, 2020 6:20 PMNEW YORK (REUTERS) - Tennis players throwing rackets and hitting balls away in anger and frustration during matches are regular scenes on the circuit, but those could be a thing of the past after Novak Djokovic's disqualification from the US Open on Sunday (Sept 6).