Dieter Zetsche, the chairman of the Daimler board, has warned against expecting "miracles" from Mercedes this season.
Last year, Mercedes started strong with Nico Rosberg winning the Chinese GP, however, as the campaign progressed they dropped off the pace and finished a distant fifth in the Constructors' Championship.
This year, the Brackley-based squad is hoping for better and has shown some encouraging signs during pre-season testing.
However, Zetsche was warned against setting high expectations.
"All these years the team has had great engines - perhaps the best in Formula One - and great riders so the cause of the lack of success was the uncompetitive chassis," he told F1news.ru
"The team has not been able to perform at a level consistent with the starts of Mercedes so a change in leadership was needed and we have two new and high qualified specialists - Toto Wolff and Niki Lauda.
"The immediate effect of this change will not see miracles expected in the upcoming season but after the transition to the new engines in 2014 we will have a chance to realise our goals."
As for rumours that Mercedes could withdraw from F1, Zetsche said: "There is no point in discussing this possibility.
"We would like to continue to use this excellent platform for the benefit of our company."
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