Former US Open champion Emma Raducanu has split with coach Sebastian Sachs, her fifth coach in less than two years.
Sachs joined the Briton's team in December after former coach Dmitry Tursunov warned of "red flags".
Raducanu was forced to miss the French Open and will not return for Wimbledon this year as she recovers from minor surgeries on her ankle and hands.
The 20-year-old has now dropped out of the top 100 in the women's world rankings.
"I have really enjoyed Seb's coaching and working with him, it's unfortunate that circumstances made it unfeasible for both of us to continue right now and we have decided to part ways," Raducanu posted on her Twitter account.
"I wish Seb all the best moving forwards."
Raducanu's 2021 US Open win is her only singles title as she has struggled with injuries and a revolving door of coaching staff.
She has played only 10 WTA Tour matches in 2023, winning just five, with three of those victories coming at Indian Wells before a defeat by Polish world number one Iga Swiatek.
The lack of match wins has resulted in Raducanu's drop to 107 in the rankings, meaning there are no longer any British women in the top 100. She will not qualify automatically for this year's US Open and would need to either progress through qualifying or be given a wildcard to compete there - providing she is fit enough to do so.
The absence of British talent in the singles at this year's Roland Garros drawn criticism as only three men and no women qualified for the main draws. Britain's highest seed Cameron Norrie, the world number 13, is the lone remaining competitor after Dan Evans and Jack Draper bowed out in the first round.
Draper is another promising young British player who has been hampered by a series of injuries, having retired from his first-round match In Paris against Argentina's Tomas Martin Etcheverry with a shoulder issue.
