Mercedes boss Toto Wolff says he fears all rival teams ahead of the start of the 2017 season.
After three years of Mercedes domination, new regulations for 2017 could shake up the order with more emphasis shifting towards aerodynamics. The new formula is designed to significantly reduce lap times by fitting the cars with wider tyres and increasing downforce from the wings and diffuser.
The last major aerodynamic rule change saw Brawn GP emerge as the team to beat, just months after Honda pulled its backing from the outfit over the winter. Wolff says a similar outcome is possible this year and is therefore keeping an eye on all the teams, not just those with the biggest budgets.
"In a regulation change you need to fear everybody," Wolff told Radio 5 Live. "Nobody would have expected Brawn to be a championship contender in 2009, so we look at everybody and there is opportunity for everybody."
Asked if he was nervous about the new season, Wolff said: "I was nervous four years ago, when we started our journey, whether we would be able to win races and championships and we have done that in the last years, so the nervousness has gone a little bit. But equally there is a bit of risk that we would fall in the trap of being complacent, so this regulation change comes at the right time [for Mercedes].
"We are super motivated in getting it right and we would be the first team to succeed at getting out of the blocks well during a regulation change [having dominated the previous year], but it's not a given.
"We don't know, there could be the odd silver bullet like Ross [Brawn] had in 2009 with the double diffuser and we will probably see at the second Barcelona test if somebody has a new innovation on the car that the others haven't spotted."