Dr Helmut Marko is predicting a "three-way battle" for the 2019 world championship.
Most predictions after winter testing agree that Ferrari is leading Red Bull-Honda and Mercedes as the sport heads to Australia.
That is despite the fact that some observers say the new Red Bull-Honda works collaboration is a "question mark".
But Marko, a top Red Bull official told Kronen Zeitung newspaper, said of the 2019 title fight: "It will probably be a three-way battle between Vettel, Hamilton and Verstappen."
Verstappen agrees: "It (the car) feels good to me, and everyone seems very satisfied and focused."