The two best men's players in the world are reconfiguring the sport before their opponents' eyes. They don't know what to do about it

Carlos Alcaraz was in fine form as he cruised to a first-round win at the Australian Open, but it was his comments on Jannik Sinner which drew attention.

Naomi Osaka, a two-time champion in Australia, stopped playing because of a strained abdominal muscle after dropping the first set of her match against Tokyo Olympics gold medalist Belinda Bencic.