Mercedes motorsport boss Toto Wolff admits his squad "need to be careful" in the battle for the Drivers' Championship following their poor display in Hungary.
With the W06 the fastest car on the grid, many believed the assault on the title would be a straight fight between Merc duo Lewis Hamilton and Nico Rosberg after the pair won eight of the first nine races.
However, Sebastian Vettel of Ferrari claimed his second win of the season in Budapest on Sunday and, coupled with Mercedes' nightmare display with Hamilton's P6 their best result, the German finds himself now 42 points behind the Briton in the standings while he is only 21 points adrift of second-placed Rosberg.
"We just need to be careful," Wolff is quoted as saying by Autosport.
"We're 42 points ahead in the Drivers' Championship, but you can see how quickly it goes when you have a bad day and the car doesn't score good points – boom! You go backwards.
"That is the mentality we have anyway, of always being a bit skeptical about how we are doing, and we received further proof in this race."
With Merc dominating during the early stages of the season, it was put to Rosberg that maybe he was too focused on staying ahead of Hamilton in Hungary on Sunday that he forgot about the Ferraris and allowed them to open a big gap.
"We are always aware of our opponents but naturally we are both fighting for the race win, so the focus is a bit on Lewis," he said.
"But our car is still awesome. We don’t understand what happened. We will be quick in Spa."