The 19-year-old, who stunned the tennis world by winning the US Open qualifier last year, is now looking for a fourth coach in less than a year.
Raducanu’s departure from Germany came as a surprise to many as he continues his work on clay before attending his first French Open next month.
“Turban is a very good man,” he told reporters ahead of the Madrid Open this week. “I really enjoyed my time with him inside and outside the court.
“He’s one of the best people I’ve ever met, so obviously it was hard to break up with someone like that, but I think I’m very comfortable with my current training.
“Turbine has been great for me because when I wanted someone with a tour experience, I think the first six months of that tour were very valuable.”
However, he did notice a significant improvement in the difficult start of the year, during which he was knocked out of the first round by lower-level opponents and also dealt with injuries.
“Going forward, I’ll probably put a lot of emphasis on arguing,” Radukano added.
“It’s getting clearer to me, as I spend more time on tour, it’s just that these girls are getting used to the speed of the ball.
“I like to combine it. I especially like to work and I’m very clear about what I want to work on. Most of the time these ideas come from themselves.”
Raducanu will face Czech world number 49 Teresa Martinkova in the first round in Madrid on Friday.