Pitting Lewis Hamilton against Sebastian Vettel at Red Bull would risk the harmony of the team.
That was the message of Christian Horner on Tuesday as the team principal finally dealt a knock-out blow to speculation linking McLaren's Hamilton with a 2012 switch.
It emerged this week that Hamilton, 26, handed over to Horner a business card of his new manager Simon Fuller in Montreal and will be free to sign a Red Bull contract if he is not crowned 2011 champion.
But Horner, indicating Mark Webber is very likely to be offered a new contract, has told British reporters ahead of Silverstone this weekend that he has "severe reservations" about signing Hamilton.
"A Hamilton-Vettel combination, on paper, would look very attractive. But what we have to look at is the dynamics of a partnership and it's difficult to see how two sportsmen at the absolute top of their game could work in harmony under one roof," he said.
"History demonstrates, whether you look at Alain Prost and Ayrton Senna or Nigel Mansell and Nelson Piquet, that it doesn't tend to work. Lewis is one of the top three in the world but we are very happy with the combination we have.
"Lewis must be very frustrated this year. But it be would be difficult to envisage a driver of Sebastian's calibre and one of Lewis's under the same roof," added Horner.
The comments might be regarded as insulting to both Hamilton's current teammate Jenson Button and also Australian Webber, with the implication that Horner does not regard them as truly top drivers.
Lewis is one of the top three in the world
There also might be a deeper relevance ahead of the 2012 talks with Webber about his role at Red Bull.
"We are not looking for anybody else. I don't believe Mark is looking to go anywhere else," said Horner. "When the time is right we will sit down and have what is hopefully a very straightforward conversation.
"We are very happy with the job Mark is doing."
Webber, who is 35 in August, told the Telegraph: "We are talking but there is no real urgency from either side."