Coco Gauff has made improvements to her serving and her forehand. And the strides in both of those areas are among the reasons she's considered one of the few women ready to challenge two-time defending champion Aryna Sabalenka for the title at the Australian Open.

Given everything she has already achieved in her fledgling career – and the weight of expectation she has borne as one of tennis’ rising superstars – it’s sometimes easy to forget that Coco Gauff is still only 20 years old.

It was a meaningless hit-and-giggle session, so Coco Gauff was calling out how fast she would try to hit some serves.