Dhaka, Aug. 23 -- American world number three Coco Gauff has turned to a biomechanics expert, who helped rival Aryna Sabalenka overcome her serving troubles, on the eve of the US Open.Gauff, 21, decided to reshuffle her coaching team after hitting a high amount of double faults in her last three matches at the recent Cincinnati Open.

Matt Daly - a grip specialist who paid particular attention to her serve and forehand - has paid the price and left his role with Gauff, despite helping her win the French Open title in June.Instead, she has been working with technique coach Gavin MacMillan, widely credited with improving Sabalenka and enabling her to win three Grand Slam titles, on the US Open practice courts this week.

Gauff's other Coach...