Coco Gauff hired Gavin MacMillan, a biomechanics coach credited with rebuilding No. 1-ranked Aryna Sabalenka’s serving motion in 2022.

Gauff is currently the WTA World No. 3 with a record of 35-12 with one singles title (Roland Garros). She won the 2023 US Open, but failed to defend her title last year. Less than a month later, she fired coach Brad Gilbert.

Aryna Sabalenka says it took two weeks for her to see a ‘big difference’ in her serve after working with Gavin MacMillan. Gavin MacMillan’s effect on Aryna Sabalenka’s ser