Raducanu was followed to four tournaments by the same man, who approached her near the player hotel in Dubai the day before her second-round match with Karolina Muchova.

He gave her a letter and took her photo, which understandably unnerved Raducanu, who had been aware of his presence at tournaments in Singapore, Abu Dhabi and Doha in preceding weeks.

Although she reported it to a member of her team, the information was not passed on to the WTA or the tournament until the following day, leaving security staff with just a few hours to prepare.

After taking a week off, Raducanu decided to return and play at Indian Wells.

“They were very emotional weeks, because it had carried on for a few weeks before,” Raducanu said.

“It was quite tiring. I took a week break when I got home in England and I then decided to come here.”

Having decided to make the journey to Indian Wells – one of the biggest events outside of the four majors – Raducanu has been surprised by how much happier she has been feeling since arriving in California.

Raducanu will play Moyuka Uchijima of Japan in the first round on Thursday, with the winner to face American third seed Coco Gauff in round two.

“Since being here in this environment, which is one of my favourite tournaments, I have felt a lot better,” Raducanu said.

“The allure of Indian Wells was a big part of me coming. I wasn’t sure if I was going to come and compete so soon.

“I just wanted to make sure I was ready but since coming here I have surprised myself with how happy I feel here.”