The former coach of Lydia Ko says pressure from her family is affecting the world number one's game.
David Leadbetter announced today his three-year coaching relationship with the 19-year-old was over.
In an interview with Radio Sport, he hinted that her parents had made his life difficult this year.
"My advice to the next coach is it has to be a coach one on one, you can't have the parents involved otherwise it is not going to work," he said.
"We have had a pretty good relationship but it is not easy coaching three people at once."
Ko won four times on the LPGA this year, and won a silver medal at the Rio Olympics.
However, her form tailed off as the season progressed.
Leadbetter suggested Ko's father was behind the decision to get rid of caddy Jason Hamilton in October.
"Her father has got a little bit more involved, trying to throw some swing technique at her. Changing her caddy was a crazy decision. Her parents are lovely people but I think they are little naive."
He said Ko needed to take control of her game, and her life.
She has not commented on the split.
"Own your game. You are the player, you need to make these decisions."