John McEnroe thinks Alexander Zverev doesn't have a reason to concern himself about what some may say about his road to a possible Australian Open title as the American tennis legend says no one will remember in a decade that Novak Djokovic from their semifinal match.

Alexander Zverev chided the crowd after they booed Novak Djokovic for retiring due to injury after the first set in an Australian Open semifinal.

Novak Djokovic is out of the Australian Open in stunning fashion. The 24-time slam champion medically retired immediately after dropping the first set of his semifinal match against No. 2 Alexander Zverev in a tiebreak 7-6 (5).