He is the coach of one of the sport’s all time greats – Serena Williams – but Patrick Mouratoglou has received severe criticism for his methods from a former protege of his, according to a report by Yahoo Sports.

Aravane Rezai, a former world No 15, has accused Mouratoglou of being “a better businessman than a coach” for the pressure he put on her during their association.

Mouratoglou coached Rezai in 2009 and the Iranian–French tennis player said she felt like she was “in prison” during that time.

Mouratoglou has been working with 23-time Grand Slam champion Williams since 2012 and has also been associated with up-and-coming Greek star Stefanos Tsitsipas.

“He is a man passionate about tennis, you can see that he cares,” Rezai told Spanish tennis blog Punto de Break. “I would not say that he is a great coach, but he is a great businessman: he knows how to play, how to analyse things from a tactical point of view.

“I was put under enormous pressure to win. I couldn’t unwind, I couldn’t take the phone, the credit card, anything. It was like being in prison. I would get up at six in the morning to run an hour or two, do the physical training before my training, it was too much. That is why our relationship lasted just over a year. The people around me told him that I couldn’t take it anymore, but he replied that he didn’t care. He didn’t care about my mental health.”

Mouratoglou was in the news recently for planning a league of 50 matches at his academy near Nice in the south of France with “millions of US dollars in prize money”. The league is set to be broadcast live under the title “Ultimate Tennis Showdown” starting on the weekend of May 16.