Mercedes are playing down their chances of repeating Nico Rosberg's maiden victory at Shanghai last year in next Sunday's Chinese Grand Prix.
Motorsport director Toto Wolff said last year's triumph does not mean the team can realistically target the same result next week despite an encouraging start to the season following the arrival of 2008 champion Lewis Hamilton.
Hamilton quit McLaren as successor to retired seven-time champion Michael Schumacher.
The Englishman has suggested after two impressive season-opening events in Melbourne and Kuala Lumpur that Mercedes are now the second best team behind Red Bull.
But Wolff said: "One year on from Nico's win, a lot of people will be asking whether this is something our team can repeat in 2013, but like they say, yesterday's home runs don't win today's games, and that's definitely true for us," he said in reflection over the German driver's victory.
"We start again from zero this year and need to work hard to adapt the car to suit the circuit and the tyre compounds we have available, in the conditions that we find on the track next weekend.
"Then we will see where we stand, relative to the competition. We have made a solid start to the season in the first two races with Nico and Lewis both performing at a very high and equal level.
"The development race will be critical this season so we have more new parts planned for China. Our aim has to be to improve on our good start to the season and continue scoring good points in both championships."
Hamilton scored his maiden podium with Mercedes last month in Malaysia where he finished third behind feuding Red Bull duo Sebastian Vettel and Mark Webber, but admitted he is not expecting his team to emulate last year's performance.
"I think Mercedes were in a unique situation last year at the track and they got everything right," said the 2008 world champion.
"The tyres are different this year so you have to anticipate that it's going to be a little bit different there for us.
"Walking off into the distance is probably not going to be the case. If the car works well there and we get a similar result there, it'll be amazing."