Formula One: Red Bull still a threat says Mercedes boss

Mercedes driver Lewis Hamilton, right, celebrates his win with third placed Red Bull Racing driver Sebastian Vettel on the podium after the Malaysian Formula One Grand Prix. Photo / AP

Mercedes F1 boss Toto Wolff believes Red Bull have provided his team with "a necessary wake-up call" following their remarkable early-season revival.

Throughout pre-season testing reigning champions Red Bull suffered a litany of technical issues, and by the first grand prix in Australia just over two weeks ago had not even completed a race simulation.

Yet at Melbourne's Albert Park, and again in Malaysia on Sunday, it has been Red Bull who have at least posed Mercedes a threat in the face of the Brackley-based team's superiority.

Despite Daniel Ricciardo's disqualification from his home race Down Under due to a fuel-system irregularity - which is under appeal - the fact he was runner-up to Nico Rosberg served notice Red Bull were finding solutions.

At Sepang, the wet conditions in qualifying undoubtedly came to Red Bull's aid as Sebastian Vettel came within a fraction of a second of pipping Lewis Hamilton to pole.

During the race itself, although Hamilton sailed off into the distance to claim the 23rd win of his Formula One career, Vettel managed to hound Rosberg for the majority of the race en route to finishing third.

Wolff appreciates Mercedes may have the edge now, notably clinching the marque's first one-two for 59 years in Malaysia, but he has no doubt Red Bull will push them all the way.

"Everybody is very proud at Mercedes we finally achieved the one-two," said Wolff.

"However we cannot be complacent because we saw a Red Bull ride up our arse - I know that's not politically correct.

"But given they missed out on two thirds of testing, it's a good wake-up call for us, a necessary wake-up call."

-AAP