Rosberg: The weakness Lewis has is a bit of inconsistency

Speaking ahead of the season-opening Australian Grand Prix weekend, Rosberg said, "The weakness Lewis has is a bit of inconsistency. He has these periods when he is just not on it."

"If you are able to pounce in those periods and really make the most of it, you can keep him down for a while longer. You have to make the most of it, absolutely, and Sebastian did that pretty well last year.

"When Lewis has his good weekends he is almost unbeatable, he is unbelievably fast and maybe the best guy out there."

"The only way to beat Lewis is to be 100 percent with everything, do the perfect season. Otherwise, there is no chance."

Last year Rosberg's replacement Valtteri Bottas was not too shabby during the first half of the season but after the summer break, Hamilton upped it a gear or two and the Finn did not get a look in until after the title was decided.

Rosberg said, "I hope that Valtteri can be even closer to [Lewis] this year, because last year he showed some really big flashes of brilliance but it just lacked in consistency."

"I think he can do it, I think he can really ramp it up even further and get very, very close. That is what we want to see, we want to see a good internal battle there."

Mercedes start the season clear favourites, as for their rivals Rosberg opined, "Then Sebastian has to be the next one as a big challenger for Lewis. For Kimi, looking at last year, it will not be so easy but maybe he can find a little bit extra this year."

"Then the Red Bull guys it depends on their car. If the car is good, those two are some of the most exciting prospects and when they are up in front there is always action happening," concluded the 2016 Formula 1 World Champion.

Rosberg is to join Sky Sports F1 as a pundit for key races throughout the 2018 season, beginning with the opening race weekend in Melbourne.