Nico Rosberg has admitted that Mercedes may have no answer to Red Bull's pace around Monaco after Daniel Ricciardo dominated second practice by more than six-tenths to Lewis Hamilton.
Although Mercedes have pace in hand – often hiding their ultimate performance until qualifying – Rosberg doesn't believe they can make up that much of a deficit by simply turning their engines up to the maximum.
"It's very simple, they [Red Bull] were faster than us," Rosberg said. "We need to dig into it and see if we can find a big chunk of lap time. Of course we can turn up the engine, but we don't have 0.6s of turning up the engine.
"Definitely it's surprising how quick they were. We expected them to be there or there abouts, but not that quick."
Although Red Bull won last time out in Spain, victory was handed to them when the Mercedes pair crashed out on the opening lap. However the team believe they are a legitimate threat to Mercedes in Monaco, and Rosberg agrees.
"Am I confident [I can take pole]? No, because Red Bull is quicker. I'm really confident we can do a great job to improve the car, but will it be enough? I don't know."
