Pascal Wehrlein has said that Mercedes did not sign him up for 2017 in order to safeguard the longevity of his Formula 1 career.

German Wehrlein, 22, is the senior member of Mercedes's driver development programme and was therefore a favourite when Nico Rosberg announced his shock decision to quit F1 late last year.

Ultimately, the older and more experienced Toto Wolff-linked driver Valtteri Bottas was signed up for 2017, on a mere single-season contract.

"Toto told me he didn't want to burn me," Wehrlein told Germany's Sport Bild.

"He said they still believe in me and that I should instead build myself up in peace. Of course I hoped for a change to the world champion team, but when Mercedes went for Bottas, I wasn't too disappointed.

"Why? Because my original 'plan A' was still fulfilled."

That 'plan A' was the 2017 move from the backmarker Manor to Sauber, a more established midfield team.

However, winter testing has shown that, after almost collapsing last year and now set to use Ferrari's 2016-spec engine this year, Sauber will almost certainly be F1's new backmarker in 2017.

Still, Wehrlein is happy, saying: "Sauber is at the beginning of an era. There is enormous potential in the team and I am proud to be a part of this building back up. We have a highly professional, international team."

For instance, Wehrlein said that he was blown away by Sauber's state of the art wind tunnel at Hinwil, adding: "As I said, I think there is huge potential in the team.

"But we will have to have a little patience."

The 2017 championship kicks off with the Australian Grand Prix next Sunday.