Nico Rosberg believes former teammate Lewis Hamilton is going through a "typical" tough patch at the moment and says Sebastian Vettel missed a trick by not getting a better result in China to capitalise on it.

Hamilton struggled to get the best from his Mercedes throughout the Chinese Grand Prix weekend, failing to get his tyres up to temperature in qualifying and suffering with an overheating front left in the race. Rosberg, who was Hamilton's teammate and closest rival between 2013 and 2016, believes it is only a matter of time until the four-time world champion finds his form again and says his title rivals need to make the most of his current struggle while it lasts.

"Lewis, for him, he was really struggling", Rosberg said in a video on his YouTube channel. "He was struggling all weekend and doesn't really understand [why], looking at his interviews.

Nico Rosberg retired from Formula One after beating Lewis Hamilton to the title in 2016, JOHANNES EISELE/AFP/Getty Images

"It's a typical phase for Lewis when it doesn't go perfectly and he starts to lose that edge a little bit, lose a touch of motivation and then he just struggles for a while. Usually he struggles for one, two or three races, and those are the races when as his opponent in the championship you have to maximise, and Sebastian failed to do that [in China].

"That's a big setback for him as well because Lewis always come back and when he comes back he comes back so damn strong that he's almost unbeatable. Let's see when that happens."

Rosberg was also vocal about Max Verstappen's performance after the Red Bull driver threw away a potential victory in China following a botched overtaking move on Hamilton and a collision with Vettel.

"He's one of the big talents out there and has a great future but driving the way he is at the moment he's not going to be able to be world champion," Rosberg said of Verstappen. "Five mistakes in three races, and five major mistakes, it's too much.

"Today was one of those extremely hard days for a young driver where you take the championship leader out, take yourself out, you get a penalty, you are 100 percent at fault and your teammate wins the race in an unbelievably awesome way. That is a hard day, that's painful.

"Those are the days when a young driver like Max, hopefully for him, will learn and adapt."