An unhappy internal atmosphere will plague Ferrari's 2020 season, according to Zak Brown.

McLaren supremo Brown will lose his driver Carlos Sainz to the Maranello team for 2021, with Ferrari having signed him to replace Sebastian Vettel.

Vettel, however, will race in 2020.

"I doubt there will be a great environment in the Ferrari garage this year," Brown is quoted by Corriere della Sera. "It doesn't seem like a happy family at the moment.

"I think what we saw in Brazil last year will be a preview of what we will see this year," he added, referring to the on-track clash between Vettel and Charles Leclerc.

And Bild newspaper reports that the relationship between Vettel and Ferrari has diminished even more after Mattia Binotto thanked Charles Leclerc for forgoing 25 percent of his salary in 2020.

The Ferrari boss did not mention Vettel.

Zak Brown thinks the German driver will quit Formula 1 at the end of 2020.

"He doesn't seem to have a chance at Mercedes or Red Bull, so the best he can choose is Renault," he said. "Will Seb want to go to a team that probably won't be able to win in 2021?

"Unless he wants to start another long journey, I think in the end, unfortunately, he will decide to stop."