Sebastian Vettel says his 2019 season has been "ok".

The quadruple world champion is currently embroiled in rising tension with his highly rated young teammate Charles Leclerc, who has won two races in 2019 compared to Vettel's one.

To the German magazine Sport Bild, Vettel said he gives his performance a rating of '2 minus'.

"I think overall it was ok, for me it's just important to understand what happened this season," said the 32-year-old.

"If you're honest with yourself, not just in the area of sports, you always know whether you have given everything or whether you could have done something better."

Amid the rising tension with Leclerc after the latest team orders affair, Vettel was at Maranello this week for a meeting with team boss Mattia Binotto.

One potential theory is that Binotto proposed that Vettel become the 'number 2' for Leclerc in the final year of his current Ferrari contract.

"I think Sebastian will still drive in 2020," Gerhard Noack, a karting guru who worked with Vettel and Michael Schumacher, told Kolner Express.

"What happens after that is written in the stars."

Vettel was asked how it feels to be slumping in his fifth year at Ferrari, whereas his hero Schumacher won the title for Maranello in the same period.

"It's not like there is a blueprint for how to become a German world champion with Ferrari. You can't just compare eras like that," he insisted.