LONDON (Reuters) - Lewis Hamilton and Sebastian Vettel boast 10 Formula One crowns between them but Red Bull have the "coming man" in Max Verstappen and would say no to both, according to team boss Christian Horner.
The two champions are out of contract at the end of the season, by which time 35-year-old Hamilton could have equalled Michel Schumacher's record seven titles.
Hamilton is expected to stay at Mercedes but has also been linked to Vettel's place at Ferrari, whose long-term focus is on 22-year-old Monegasque Charles Leclerc.
Red Bull have 22-year-old Verstappen, widely seen as Hamilton's heir apparent, under contract to the end of 2023 and Horner hailed the Dutchman as the "most in-form driver in F1".
"He (Hamilton) wouldn’t fit into our programme," Horner told reporters at a recent Red Bull team event.
"We have Max. We have always taken the policy if investing in young talent, nurturing and developing that talent. Lewis doesn’t fit into that."
Vettel, 32, won his four titles with Red Bull between 2010 and 2013 but Horner made clear that was now a closed chapter in the team's history.
Asked whether he would have Vettel back, Horner replied: "It's difficult to see how two alphas can fit in a team. You can see the problem that Ferrari have had. Why would it be any different at Red Bull with two alpha drivers?.
"Same with Lewis at Ferrari or Lewis at Red Bull. That is a very difficult dynamic, especially in a tight competition."
Horner said he expected Hamilton to stay on at Mercedes, but warned that the champion might have to tone down his wage demands.
The Briton is estimated to be earning in the range of 40 million pounds a year at present.
"Two of the major seats are now filled. Logic would say that he’ll remain in his current team if they can agree terms," said Horner.
"All the automotive sector have got financial pressure at the moment, so when there’s redundancies being made I guess it’s difficult to justify record-breaking salaries.
"I would assume it will be a normal commercial negotiation between the driver and his team. Ferrari could be a possibility for him, how much is difficult for me to gauge.
"He seems happy in the environment he's in. If it's the most competitive environment, why would he want to change that for the sake of driving in a different colour? So I don't subscribe to that theory."
Horner said Verstappen had the experience to put a championship challenge together and this year, with the youngster partnered by Thai racer Alexander Albon, could see the change at the top.
"The likelihood is that Max is the one most likely to have a go at (Hamilton), and that's inevitable," he said. "There is always another wave coming.
"Max is the coming man. He is 22 years of age; he is in the ascendancy. Lewis is, what, 35?. It is inevitable in any sport, there's always another generation coming.
"And I think Formula One, with Max and Leclerc and the other youngsters coming along, is set for a really thrilling year."
(Reporting by Alan Baldwin, editing by Ed Osmond)