Losing a chance for a Grand Slam title is a key source of consternation for the doubles players.
When Murray won his third consecutive US Open mixed title with Bethanie Mattek-Sands in 2019, the pair celebrated by drinking champagne out of their trophy at JFK Airport.
Many doubles players, including Murray, believe the star-studded event could complement the traditional mixed – but not replace it.
“I’m sure it will be an entertaining exhibition – but that’s what it will be. I don’t see it as winning a Grand Slam,” Britain’s Joe Salisbury, who reached the Wimbledon mixed doubles final with Brazil’s Luisa Stefani last month, told BBC Sport.
Another gripe is the lack of consultation.
Salisbury and Stefani’s understanding is the US Open did not discuss the plans with the players, who are represented by elected Association of Tennis Professionals (ATP) and Women’s Tennis Association (WTA) councils.
Pegula, a prominent member of the WTA council, agreed the USTA went “rogue”, adding: “If there was feedback about the format, then the [reaction] would be a little different.”
“I’m sure there would have been resistance,” Stefani said.
“But our views wouldn’t have mattered anyway. The decision was made and we have to live with it.”
In an already packed calendar, the timing is also tricky with many players competing in warm-up tournaments before having to dash to Flushing Meadows.
On Monday, five-time Grand Slam champion Alcaraz won the Cincinnati Open and said: “The scheduling isn’t the best, playing tomorrow. But the concept of the tournament – I love it.
“Probably going to sleep late but I’ll try to put my best tennis to help Emma [Raducanu] get the win.”
As the start date has drawn closer, withdrawals have also become a concern with Paula Badosa and Tommy Paul pulling out along with Sinner’s partner Emma Navarro.
The Italian top seed has been repaired with Katerina Siniakova but there are doubts over Sinner’s own participation after he retired from the Cincinnati Open final against Alcaraz with illness.