Emma Raducanu has split from her tennis coach Torben Beltz after just five months together.
The 19-year-old US Open champion - who hired the German coach at the end of last season - hailed his "huge heart" throughout their professional relationship but insisted she needed to "transition to a new training model".
She said in a statement: "I want to thank Torben for his coaching, professionalism and dedication over last half a year.
"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."
Beltz, 45, previously worked with Angelique Kerber.
Now, Emma is searching for her fourth coach in less than a year.
She appointed Beltz after deciding no to extend a partnership with Andrew Richardson, having previously worked with Nigel Sears.
Meanwhile, the athlete previously hit out at the "unfair" response to her growing list of commercial partners after she suffered another defeat at the Miami Open last month.
She recently became a brand ambassador for the car manufacturer Porsche but the British number one insisted that she is fully focused on improving her results on court.
The tennis ace said: "Maybe you just see, on the news or on social media, me signing this or that deal and I feel like it's quite misleading because I'm doing five, six hours a day [of training], I'm at the club for 12 hours a day.
"But I throw out one post in the car on the way to practice and all of a sudden it's, 'I don't focus on tennis'. I think that it is unfair but it's something I have learned to deal with and become a bit more insensitive to the outside noise.
"At the end of the day, I feel like my days [with sponsors] are pretty limited. I'm not doing crazy days. I'm doing three, four days every quarter, so it's really not that much."