Mercedes chief Toto Wolff insists no rival team can be written off next season, not even last-placed Williams, given the scope of the rule changes for 2019.
Next year sees the introduction of major aerodynamic changes to the front and rear-wings in the hope of increasing the amount of overtaking, but it's expected to bring a major loss in downforce which teams are fighting to recover before the first race.
Wolff has warned that no team can be discounted from vaulting up the order and challenging Mercedes' dominance.
"I think with the rule changes everything is possible," said the Austrian ahead of the FIA's prize giving gala on Friday.
"It is almost like 2009 where Brawn identified the double diffuser. I think there could be teams that have found loopholes, which others didn't spot, that could make the difference.
"So we are taking everybody seriously. Whether it is Ferrari finishing second this year or Williams finishing 10th. All of them could come with a car that can outperform us.
"We are respecting all these teams and the effort they put into it and all of them are being seen as competitors."
Wolff admitted last week that Mercedes had suffered a small setback in its 2019 engine development programme, but remained confident it would be overcome.