London - Lewis Hamilton's Formula One rivals should beware the backlash because the four-times world champion's dip in form will not last long, his former Mercedes team-mate Nico Rosberg has warned.
Speaking on his YouTube channel, the 2016 world champion said last Sunday's Chinese Grand Prix showed the Briton, who finished fourth, was struggling.
The German, whose once-friendly relationship with Hamilton grew increasingly frosty in their time together, saw that as just one of those "typical phases" that his old rival goes through.
"When it doesn't go perfectly, he starts to lose that edge a little bit and a touch of motivation or whatever and then just struggles for a while," said Rosberg.
"And those are the races you have to maximise... because Lewis always comes back, and when he comes back he comes back so damn strong that he's almost unbeatable. And so let's see when that happens."
The next race is at Azerbaijan's Baku circuit on April 29.
Hamilton has not won since last year's US Grand Prix in October, a run of six without standing on the top step of the podium.
In the three so far this year, the 33-year-old has finished second, third and fourth and been beaten twice by Finnish team-mate Valtteri Bottas.
Ferrari's Sebastian Vettel won in Australia and Bahrain and Red Bull's Daniel Ricciardo in China - the first time since the V6 turbo hybrid era started in 2013 that Mercedes has lost three races in a row.
Hamilton had a longer winless run at the end of 2015 and early 2016 when Rosberg won seven in a row before Max Verstappen triumphed for Red Bull in Spain. Hamilton then won six of the next seven.
The Briton went on another five-race run without victory after that before winning the last four races, but the damage had been done and Rosberg was champion.
Hamilton said after Shanghai, where Ferrari swept the front row for the second race in succession, that he felt he was in 'no-man's land'. "Obviously it's a tough battle ahead of us. I would say on my side but also us as a team, we've been underperforming," he added.
"I have got to try and rectify that and get myself back into normal performance mode, otherwise more valuable points will be lost."
Team boss Toto Wolff agreed Hamilton's form had dipped.
"Like the car, he was maybe not in the best place this weekend," the Austrian told Sky Sports. "He's the best driver, in my opinion, but also the best ones have days where it's just not 100 percent."