In Abu Dhabi, Dr Helmut Marko insisted that Lewis Hamilton becoming Max Verstappen's teammate at Red Bull won't work for both "emotional" and "financial" reasons.
But the biggest reason, he told Kleine Zeitung newspaper, is that both Mercedes' Hamilton and Verstappen's existing teammate Sergio Perez have contracts for 2024.
Mexican Perez's performance slumped this season, sending the silly season into a long spin. But Red Bull consultant Marko says the 33-year-old has now recovered.
"The goal for him was to come second in the world championship, and he achieved that," the Austrian insists.
"He also won two races and his performances were always absolutely ok in terms of speed. The speed is back, as is the self-confidence.
"So everything speaks in his favour - not just the contract. He is our man for 2024," Marko added.
Former F1 driver Ralf Schumacher suspects that at least part of the reason for the wild Hamilton-Red Bull rumours in the 2023 finale is that the seven time world champion is frustrated with life at Mercedes.
Hamilton told La Gazzetta dello Sport in Abu Dhabi: "We are suffering because we made the wrong technical choices, both last year and this year.
"And with the budget cap in force today, it's difficult to recover. If you're technically three months behind the others, you can't catch up like you could in the past when you could spend more."
Schumacher, though, admits it is "surprising" that Mercedes still seems quite lost a full two years into the 'ground effect' era of regulations, which will continue until 2026.
"During our interviews, Toto Wolff seems either bored or somehow puzzled, and sometimes he seems completely absent," the German is quoted by motorsport-total.com.
"The team isn't falling apart but there's a feeling that something's wrong. Neither driver seems happy. It's clear that George Russell is nervous, he's thinner than usual, he's making a lot of mistakes and he's being very aggressive.
"Mercedes still have a lot of work to do," Ralf Schumacher added.
At the same time, he thinks Ferrari is steadily making progress in closing the gap to Red Bull.
"At Ferrari, everything now finally seems to be going in the right direction," said Schumacher. "Everything Frederic Vasseur is doing seems to be working."