Sloane Stephens and her Dutch coach Sven Groeneveld have already decided after three months not to continue together, the American top tennis player announced on Monday.
"After much thought, Sven and I decided to go our own way. Change is never easy, but I am grateful for our cooperation," writes Stephens on Twitter.
When Stephens and Groeneveld entered into their cooperation in May, the American was the number eight in the world. The US Open winner of 2017 failed in the last three months, including the quarter finals of Roland Garros and the third round of Wimbledon.
The 26-year-old Stephens, engaged to footballer and former AZ striker Jozy Altidore, remained on six WTA titles. She was nowhere further than the quarterfinals under Groeneveld and is now the global number eleven.
In the past, Groeneveld has worked with big names such as Maria Sharapova, Caroline Wozniacki, Ana Ivanovic, Monica Seles, Arantxa Sanchez Vicario, Mary Pierce, Tommy Haas, Michael Stich and Greg Rusedski.