US Open champion Emma Raducanu has split with German coach Torben Beltz after working with him for five months, the BBC reported on Tuesday.
Raducanu appointed Beltz as her coach in November after she had parted ways with Andrew Richardson following her surprise triumph at Flushing Meadows, where she became the first qualifier to win a Grand Slam.
The 19-year-old said she needed "a new training model" and that Britain's Lawn Tennis Association (LTA) would support her in the interim.
"I want to thank Torben for his coaching, professionalism and dedication over the last half a year," the BBC quoted her as saying in a statement.
"He has a huge heart and I have enjoyed our strong chemistry during the time together.
"I feel the best direction for my development is to transition to a new training model with the LTA supporting in the interim."
Reuters has requested comment from Raducanu and the LTA.
Raducanu, ranked 11th in the world, lost to world number one Iga Swiatek in the quarter-finals of the Stuttgart Open last week.
New Zealand overcame a blitz from centurion Harry Brook to beat England by four wickets on Sunday in the opening game of their three-match one-day international series, with Daryl Mitchell and Michael Bracewell scoring half-centuries.
Belinda Bencic breezed past Czech sixth seed Linda Noskova 6-2 6-3 to win the Pan Pacific Open title on Sunday, erasing bitter memories of her straight-sets defeat by Agnieszka Radwanska in the title clash of the same tournament 10 years ago.
Liverpool manager Arne Slot said opponents have identified a winning strategy against his Premier League champions and he needs to find a solution fast after a 3-2 defeat at Brentford on Saturday made it four league losses in a row.
Rohit Sharma hit a century and Virat Kohli a bright 74 to drive India to a nine-wicket win in the third one-day international on Saturday, sending fans home happy after what are likely to be their final appearances in Australia in their country's colours.