Emma Raducanu's agent insists the US Open champion is not being distracted by commercial interests.
Max Eisenbud, who also guided the careers of Maria Sharapova and Li Na, says Raducanu's win in New York sparked unprecedented interest from the corporate world.
And he maintains his company IMG has "left million of dollars off the table" by limiting Raducanu to a maximum of 18 sponsor days a year.
"We could have done 50 days of shoots," Eisenbud told The Sports Desk podcast.
"I've never seen the amount of excitement and companies that wanted to be in business with Emma after the US Open."
Raducanu is a brand ambassador for nine companies, from Evian to Tiffany, and Nike to HSBC.
The contracts range from three to five years in duration, and are worth tens of millions of pounds.
Raducanu's year on the court, though, has so far been less profitable. The 19-year-old has won just eight of the 19 matches she has played so far this season, and experienced a string of minor injuries.
But Eisenbud says people should not draw a link between those difficulties and her commercial interests.
"It's been a tough year," he admitted. "I think she got a lot of bad luck and what really hurt her was [catching] Covid and not having a great off-season, and then she was playing catch up.
"But I think that if she had zero shoot dates, everything would be the same.
"I know from the outside, you guys want to look at all those things - but if she locked herself in the room for the whole year and didn't do anything, I think it would be the same."
Eisenbud says this is his third professional experience of something "spectacular, special - and not normal".
The other two were a 17-year-old Sharapova beating Serena Williams in the Wimbledon final of 2004, and Li being watched by an estimated 116 million Chinese viewers as she captured her first Grand Slam title at the French Open of 2011.
Eisenbud recalls renting a room for a meeting with Sharapova's father Yuri shortly after her 2004 Centre Court triumph. He says Yuri wanted to capitalise on his daughter's victory, but also ensure she stayed focused and kept winning.
The American's response was to draw up a calendar, and then strike a line through all the weeks - primarily before, during and immediately after a tournament - where they both agreed there was no time for commercial work.
"So we did this exercise through the entire year and we figured out that there was probably 18 days a year that she can give to sponsors that won't affect her tennis training or her tournament schedule," Eisenbud said of a player who for a decade was consistently the highest earning female athlete in the world.
A few years later, Li's family decided they liked the sound of that approach, and it is a model which has now been agreed by the Raducanus.
"Again with the same philosophy,' Eisenbud continued. "Never a week or so before a tournament, never in a tournament week and never right after the tournament. I understand how people who don't understand that philosophy could think that it is distracting her, but I think when you see how it's laid out, it really is not the case.
"Emma decided that she wants to start her shoots at 12pm or 1pm and go until 8pm or 9pm and have the option in the morning to either train or work out or do some fitness.
"Not all the days have been used of the 18. There are sponsors that have those days, but many of them don't use them.
"I would imagine by the end of the year the amount of days she uses will be around 13.
"But when the 19th day comes, and it's millions of dollars and you have got to say 'no' because you're being true to the 18 days - it's tough."