However, since hiring biomechanics coach Gavin MacMillan, Gauff has shown clear signs of a return to form: most noticeably in Wuhan, where she defeated Jasmine Paolini and Jessica Pegula in the final two rounds.

Gauff, who was just 15 when she burst onto the scene big time and upset Venus Williams at 2019 Wimbledon, celebrated her 21st birthday in March. The American may be 21 but the majority view her as a veteran and someone who has been on the Tour for a long time.

Gauff is currently the WTA World No. 3 with a record of 47-14 with two titles. Her final tournament of the year will be the WTA Finals in Riyadh, where she will try to defend her title against the sport's top eight players. Stay locked into Sports Illustrated's Serve On SI for all of your tennis news from the court and beyond.

Coco Gauff made a brave decision to change her coaching team ahead of this year’s US Open. The American star parted ways with Matt Daly just after crashing out of the Cincinnati Open, which led to her hiring Aryna Sabalenka’s former biomechanics coach,

After posting a stunning 0-2 record during the grass season and seeing her serving woes continue at the start of the North American hard-court swing, the American tennis star made a radical move just a week before the start of the US Open as she replaced coach Matt Daly with biomechanics expert Gavin MacMillan.