Nico Rosberg says Lewis Hamilton's rivals must make the most of his current dip in performance because he "always comes back" stronger.
Although Hamilton was quickest in Australia but failed to win the race when a Safety Car mixed up the result, he struggled in Bahrain when he qualified fourth – although started ninth after a gearbox penalty – and again struggled in China at a circuit where he usually shines.
His former Mercedes team-mate, 2016 champion Nico Rosberg, insists the dip is a "phase" and has no doubts Hamilton will bounce back, it's only a matter of when, not if.
"When it doesn't go perfectly, he starts to lose that edge a little bit and a touch of motivation and then just struggles for a while," said Rosberg on his personal YouTube channel.
"You have to maximise those races because Lewis always comes back.
"When he comes back, he comes back so damn strong that he's almost unbeatable," warned the German, adding: "Let's see when that happens."
Hamilton is currently second in the championship standings, nine points adrift of Ferrari's Sebastian Vettel, who claimed victory in the opening two races and qualified on pole in China, before clashing with Max Verstappen and falling back to eighth.
