Dmitry Tursunov says "red flags" convinced him to stop coaching British number one Emma Raducanu.
The Russian says he advised former US Open champion Raducanu, 19, and her team that she needed to listen to "one voice".
Tursunov, Raducanu's fourth coach in 15 months, said: "I felt like there were going to be problems later."
Raducanu won eight of 15 matches alongside Tursunov before their split two weeks ago.
"We didn't agree on the terms and there were some red flags that just couldn't be ignored," 39-year-old Tursunov told tennismajors.com.
"She's probably a two-and-a-half-year project.