Toto Wolff has said that Valtteri Bottas does not have long to get up to speed in 2017.
Recently, after the champion team signed up the Finn to replace Nico Rosberg, chairman Niki Lauda said that Bottas has four races to start emulating Rosberg's former contribution.
"I agree with Niki," team boss Wolff has now told Finnish newspaper Turun Sanomat.
In Barcelona, F1 legend Lauda said that while Bottas is only two tenths behind Hamilton on qualifying pace, the 27-year-old is further off on a long run.
Wolff said: "Valtteri does not have a lot of time to prove he can be at Nico's level, to perform well against Lewis Hamilton and help the team keep up the development direction and speed in the car.
"It is clear that Valtteri needs to learn how to swim quickly."
Wolff also said that he agrees with the growing paddock sentiment that Ferrari is looking set to be a strong challenger for the title in 2017.
