Nico Rosberg says Valtteri Bottas needs to build an "obsessive" presence alongside Lewis Hamilton at Mercedes if he is to challenge his teammate for the world title.
Rosberg, who won the world championship in 2016 and remains to date the only teammate to have beaten Hamilton to the title, says that pressure and instilling doubt are the only ways to gain a definite upper edge over the six-time world champion.
Last year, Bottas hit the ground running in Melbourne, defeating Hamilton fair and square. The Mercedes pair shared wins during the first four races of the 2019 season before the Briton won four races on the trot, inexorably setting up his title bid.
Rosberg says Bottas will need to be snapping at Hamilton's heels from the outset and shadowing his every move, from start to finish.
"Valtteri needs to always be there as a strong opponent performing with stability," Rosberg told Auto-Hebdo.
"He needs to become obsessive, so that Lewis feels his presence."
But pressure might not be enough for Bottas to fault F1's super star, with Rosberg suggesting that one also needs to "plant a seed of doubt" in Hamilton's head, something however that isn't easily achieved.
"I remember realising that Hamilton's defenses had been broken when he started playing with Snapchat during a press conference," recounted Rosberg.
"The next day, he performed poorly. It all plays a role. It may seem insignificant, but these things can unsettle you.
"Regarding Lewis, one must understand that the more you attack him and the more aggressive you get with him, the stronger he becomes.
"Instead, it’s necessary to get into his thoughts, and that is not easy. You have to plant a seed of doubt in his mind."