Sebastian Vettel has admitted he is unlikely to win the 2019 world championship.

The quadruple world champion actually went into this season as the favourite, but Ferrari's first wins only came in Spa and Monza and it was Charles Leclerc on the top step.

"We are not the favourites for this championship," Vettel is quoted by Spain's Marca sports newspaper.

"We are far, far away. You don't have to be too smart to realise that.

"But we still have some races ahead where we will be more competitive than at other places."

Indeed, Ferrari is openly admitting that Singapore this weekend will be a struggle, but Vettel says the important thing is for the Italian team to look forward.

"We must ensure that we are developing the car in the right way," he said.

"We have to make sure we are more competitive at the end of the season compared to where we are now."