Nico Rosberg has said that Mercedes need to have "a perfect weekend" if they are to beat Ferrari at the Austrian Grand Prix tomorrow.
The German finished second to Sebastian Vettel in practice two yesterday while Lewis Hamilton finished in fifth.
"They seem quick," Rosberg told BBC Sport. "On the long run they were even closer. We need to do a perfect weekend."
Qualifying is due to take place this afternoon.
Rosberg currently trails teammate Hamilton by 17 points in the Formula 1 standings.