Novak Djokovic's Davis Cup captain calls for lifetime ban after 'unacceptable' behaviour
Serbia Davis Cup captain Viktor Troiki has slammed the treatment of Novak Djokovic after he was booed off court following his retirement at the Australian Open. After losing the first set of his semi-final against Alexander Zverev, the 24-time Grand Slam champion was unable to continue and handed his German rival a walkover win.