Dr Helmut Marko has dismissed rumours Sergio Perez could be ousted before his extended two-year Red Bull contract expires at the end of 2024.
Some think Max Verstappen's former teammate Daniel Ricciardo, now the team's reserve driver after his McLaren career collapsed, is being lined up for the role.
"It's all nonsense," Marko told Sport1. "Sergio's place has never been in jeopardy and will never be in jeopardy."
Earlier this season, Perez was clearly on-form and charging to prevent Verstappen from easily winning his third consecutive drivers' title in 2023.
Then came Miami and Monaco - and criticism.
"After his rather weak performances in Miami and Monaco, I just reminded Sergio that he should concentrate on his job," Marko, 80, said.
"He didn't take advantage of the potential he had, but in Max he has an opponent who is so difficult to beat. And it's not just him, but any driver at the moment would have the same trouble."
However, Marko insists that 33-year-old Perez is "an important element in achieving the goals we have set for this year".
"We want to finish first and second in the drivers' championship and become constructors' world champion again as quickly as possible."
Some believe Red Bull is clearly positioning Perez to accept rather than fight the perception of him as a de-facto 'number 2' driver to Dutchman Verstappen.
Marko said: "He should concentrate on himself and not try desperately to beat Max. He should be there when things aren't going optimally for Max.
"Sergio's good race after the failed qualifying session in Barcelona was again the first step in the right direction."
And with Perez back on form, Red Bull can realistically target winning every single grand prix this season - an unprecedented achievement in Formula 1 history.
"In terms of sheer performance, we're capable of that," said Marko. "It's not an exaggeration to say that we're going into all the races as favourites.
"But there is also bad luck. And with 15 races still to go, something can happen very quickly. It could get us in Montreal.
"But the probability of realising this dream only increases if both drivers are capable of winning."
