But the seven time world champion also doubts Mercedes' next car will be good enough to challenge the leaders.

"It would be presumptuous if one expects us to fight for the title next year.  At the moment we are too far behind," the 42-year-old German said at the weekend during the Mercedes event Stuttgarter Sternstunden.

The German marque's competition director Norbert Haug made a similar admission.

"Under normal circumstances, you do not go from fourth to first in one jump," he said.

Mercedes' board, however, has the patience to wait, according to head of group research Thomas Weber.

"We will give (the team) the time that is necessary to get to the top," he said.