Championship leader Nico Rosberg is fast becoming a key to the 2017 'silly season'.

In Barcelona, Daimler chairman Dieter Zetsche announced that the on-form German is in fact "under contract" for next year.

But that might not quite be true, as Mercedes team boss Toto Wolff declared on Monday that Fernando Alonso might be a target for the future.

"Fernando is one of the best drivers in history and I like his character, but our priority now is Nico," he told El Mundo.

"If he (Rosberg) does not want to renew, then we will consider other options, like Fernando," Wolff added.

Now, Italy's Corriere della Sera is reporting that talks between Ferrari and Rosberg, the winner of seven consecutive grands prix until last Sunday, have begun.

Correspondent Giorgio Terruzzi said Ferrari's new interest in Rosberg is powered by moves at other top teams to spice up their respective drivers' lineups.

Red Bull has Max Verstappen, McLaren will reportedly sign up Stoffel Vandoorne for 2017, and so officials at Ferrari believe "36-year-old Kimi, though well-liked by most in the team, is considered too inconsistent".

"On the contrary, it seems Rosberg in his full maturity is always fast, strengthened by his difficult experience at Hamilton's side."

Terruzzi also said Mercedes "would be weakened by his (Rosberg's) departure, especially if he wins the title in 2016".

(GMM)