Former world number three Stefanos Tsitsipas says his father Apostolos will no longer be his tennis coach.

The 25-year-old from Greece, currently ranked 11th, was critical of his father's coaching methods after losing to Japan's former world number four Kei Nishikori in the second round of the Canadian Open on Thursday.

Tsitsipas, announcing the end of the coaching relationship, said the decision "to let this chapter and this phase close" was taken by mutual agreement.

He added that his father would continue to travel with him to provide support and assistance off the court.

"It is with a heavy heart that I inform you that my co-operation with my father as a coach has come to an end," Tsitsipas said on X.

"I prefer to keep my father in his role as a father, and only as a father."

After losing to Nishikori, who is ranked 576th in the world, Tsitsipas said he was "really disappointed", external in his father with regards to listening to him and providing feedback.

Tsitsipas, who is a former runner-up at the Australian Open and French Open, indicated he felt regret about his post-match comments.

"I realised I was wrong to talk to my father the way I did," Tsitsipas added on Friday.

"I have trusted my father with the coaching role for so many years and I consider our partnership a success.

"I'm not sure who will take over, and I'm not in a position to decide yet."