Dr Helmut Marko says he is not losing sleep over rumours Max Verstappen could be on the move.
Earlier this year, amid reports Mercedes and Ferrari want to poach the Dutchman, Marko said Red Bull would not agree to release him for EUR 100 million.
But it is now being rumoured F1’s rival top teams are in fact considering huge sums of money to tempt Verstappen, who is under contract at Red Bull for 2018 and 2019.
Marko told Bild am Sonntag newspaper: "I’m not worried. Max started with us and he wants to get his first world championship with us. That is our desire as well."
It is rumoured, however, that Mercedes’ interest is not just one way.
Marko commented: "Herr (Toto) Wolff talking with father (Jos) Verstappen is just typical formula one. I am not sleeping badly."