Andrej Antic, editor in chief of German publication ‘tennis MAGAZIN’, has known Beltz since 2006, and says the successful Kerber partnership was in large part down to Beltz’s loyalty and discretion – two things that will suit Raducanu, who generates enough headlines on her own. “You could have a beer with him in the pub, he’s friendly to anyone if you go up to him and talk to him – but in terms of Kerber he didn’t tell you a lot,” Antic says. “The secrets he would never tell, he’s a loyal person.

“Kerber always said the coach has to stay behind, and he was perfect in that. He was never a person who went in the limelight. He knows exactly his role. [Raducanu] wants a person with experience and someone who stays behind – not like Patrick Mouratoglou [Serena Williams’s coach].”

He also has a proven track record of improving players’ results. As well as Kerber, Beltz also coached Croatia’s Donna Vekic, and his two-and-a-half years with her from 2017 to 2020 saw her break into the top 20 for the first time. Though their working relationship ended awkwardly, with Vekic disputing Beltz’s public claim that their training and scheduling opinions differed, he went on to reunite with Kerber soon afterwards to more success. After two years of sketchy results, former world No 1 Kerber returned to the Wimbledon semi-finals last July, and Beltz’s presence was touted as a reason behind her transformation.

“He helps her to get loose, to be relaxed, so I think that is something he can bring,” Antic says. “He sees if the person gets too much stress, and he has a talent to relax this person.”

Raducanu has not played a competitive match since her first round loss at the Linz Open to China’s Wang Xinyu in November, and had to pull out of the Melbourne warm-up tournament last week due to only just having come out of isolation after testing positive for Covid-19.

She has two wins to her name since her US Open triumph and the eyes of the world remain upon her every move. on Tuesdat she faces Kazakhstan’s Elena Rybakina, a player ranked five places above Raducanu at 13th, and who reached the final at the Adelaide International last week, losing out only to world No 1 Ashleigh Barty.

Raducanu will need all of Beltz’s emotional and sporting intelligence to overcome her, but it is helping his young charge overcome the even greater challenges which lie ahead that will ultimately define his tenure. One thing is for sure: the world will be watching.