Dr Helmut Marko has repeated his warning that Sergio Perez does not have a "job guarantee" at Red Bull.
Ahead of the Italian GP at Monza, the Mexican brushed off speculation he might lose his seat alongside Max Verstappen due to poor performance.
"From my side there is still a year and a half to go. So I think there's no need to change anything," he said.
At the same time, however, team advisor Marko told Osterreich newspaper that while Verstappen really could win the rest of the races this year, he wouldn't put money on another Perez victory in 2023.
"Unfortunately not," he said.
"Checo drives really well at times, but he doesn't always manage to squeeze the most out of the car without making mistakes."
When asked if Red Bull is losing faith in the 33-year-old, Marko added: "He has a contract until 2024."
However, he said that is actually no "job guarantee".
"Does a job guarantee even exist in Formula 1?" the 80-year-old Austrian asked the journalist. "It is a contractual guarantee, in any case."
Former F1 driver Ralf Schumacher said after the recent Dutch GP that he can't imagine Perez remaining at Red Bull for much longer.
"Hopefully he didn't mean that his nephew Mick should replace him," Marko laughed.
Verstappen hinted last week that he would enjoy sharing a Red Bull garage with his friend Lando Norris, even though the McLaren driver is already under contract.
"He signed a long-term contract with McLaren a few years ago," said Verstappen at Monza. "That wasn't very smart on his part," he smiled.
