Sebastian Vettel has admitted Ferrari has taken an engine upgrade to Sochi.
"You know more than we do so I don’t need to say anything!" the German joked, when asked by a reporter about Ferrari’s new engine and front wing in Russia.
"I think it is quite normal these days that you bring a few new things to a race," he added.
Team boss Maurizio Arrivabene said recently that he thinks the Maranello team only lags Mercedes’ pace by a tenth, although incidents and reliability have affected Ferrari’s championship campaign so far.
Vettel said: "What the updates will bring is hard to say. The computer gives us a number but I can’t sit here and say it will be half a tenth or two tenths.
"I would love to say it will be one second, but unfortunately it’s not that simple.
"We didn’t have the first three races that we were hoping for, but I think we are in a better position than last year," he added. "It is natural to have a sense of pressure, especially from myself."
Red Bull, meanwhile, must wait until Canada in June for its new engine specification from Renault, but Daniel Ricciardo has high hopes.
"Honestly, we didn’t expect the progress we have seen from the engine so early in the season," said the Australian.
"If the update for Montreal is the same sort of step, it will be very good and given the competitiveness of our chassis, it should be enough for a serious fight with Ferrari," Ricciardo added.