Osaka's favourites: Djokovic's backhand, Barty's slice and Serena's serve

Naomi Osaka says she envies some of Novak Djokovic as he has mastered all of the basics of the game. And on the female side, her picks are Serena Williams and Naomi Osaka.

Osaka's favourites: Djokovic's backhand, Barty's slice and Serena's serve