MELBOURNE, Australia — Count Novak Djokovic as being in Danielle Collins' corner. He thinks her response to booing fans at the Australian Open was absolutely fine — which should come as no surprise, given the way Djokovic gets into back-and-forths with hecklers at his matches, including Friday night at Rod Laver Arena.

The rise of Jannik Sinner and Carlos Alcaraz vanquished Djokovic's inevitability at the Australian Open, but he is still the main character.