American world number six Coco Gauff has ended her partnership with coach Brad Gilbert just two weeks after what she described as a "disappointing" US Open title defence.
Gauff, 20, won the first major of her career in New York last year under Gilbert's guidance.
But she lost in the fourth round to fellow American Emma Navarro this year.
"Coco, at just 20 years young, your future is incredibly bright, and I wish you nothing but continued success ahead," Gilbert, who also coached former Grand Slam champions Andre Agassi, Andy Murray and Andy Roddick, wrote on X.