Pascal Wehrlein is a real alternative for Mercedes as early as next year should negotiations with Nico Rosberg falter, according to team boss Toto Wolff.

It has recently become increasingly clear that talks about extending Rosberg's stay at the German team could be fraught.

It is believed that Rosberg, assisted by family friend Gerhard Berger, is pushing for a retainer much closer to the value of Lewis Hamilton's current deal.

"Right now, our goal is to continue with Nico," Austrian Wolff told Sport Bild.

"But if we do not come together, we have to think of something else."

Wolff suggested that although Rosberg has been driving impressively over the last seven or eight months, Mercedes is also in a strong bargaining position.

"We know that we have the strongest car, a very strong team and are well positioned for the future as well," he insisted. "That would be the main argument for Nico.

"We also know what we have in him."

Rosberg currently tops the driver standings, 24 points ahead of teammate Hamilton.