Sebastian Vettel says he is not worried about the ambitions of his new Ferrari teammate for 2019.

German Vettel has had a tough few months, having gone from being world championship favourite to heftily criticised in the Italian press and beyond for throwing it away with mistakes.

Now, he has lost his preferred teammate in the form of Kimi Raikkonen for 2019, while the highly-rated incoming 21-year-old Leclerc is tipped by many to charge immediately for the title.

"Of course it will be different," Vettel is quoted by Kolner Express newspaper.

"Charles is not Kimi and Kimi is not Charles. I'm sure he wants to beat me and I want to beat him too.

"The rules of the game are clear to everyone. That was no different with Kimi. The key is that we work together on the track," the 31-year-old added.

According to some in the Italian media, the momentum at Ferrari is starting to shift away from Vettel in the wake of the 2018 failure.

La Gazzetta dello Sport correspondent Luigi Perna reports: "Confidential sources have told me that Leclerc was faster in some cases than Vettel in the same conditions in testing."