Nico Rosberg said that he thought it could go "either way" in terms of who would go into the new season with the fastest car, with the German ace predicting a serious challenge from Ferrari.
Mercedes might have led the way in terms of mileage and reliability in pre-season testing in Barcelona, but it's been Ferrari that has been topping the time sheets with Sebastian Vettel in charge on the final day of testing on the ultrasofts and his team mate Kimi Raikkonen clocking the fastest time of anyone over the entire two weeks.
"It’s gone really well for sure," said Rosberg when asked about Mercedes' performance in the eight days of testing.
"Of course the most important is the speed which we’re not 100 per cent sure of. We know that Ferrari is very close, so it can go either way really.
"They’ve been very quick, for sure, and all the teams have their strategists so we know what fuel all the others are running and they know our fuel so we know more or less where we are compared to Ferrari.
"That's why I say it’s close, but we‘re not sure if we are ahead or behind.
"That’s the most important thing, but apart from that everything else has gone really, really well. I’m definitely ready for Melbourne."
Rosberg admitted that the team was being wary about showing its true potential to its rivals this early in the year.
"You don’t really want to show to everyone else how fast you are," he said. "It’s a compromise. We did practice lower fuel with some softer tyres and all that so we did get some practice in, but it’s OK."
Paddock gossip expects the Mercedes to be significantly faster than anyone else - even Ferrari - when it comes to Australia, but Rosberg would neither confirm nor deny such expectations at this stage.
"I hope they’re right! I hope you're right!," he said. "I just say let’s wait two weeks."