Japanese GP: Sebastian Vettel will win title - Fernando Alonso

Ferrari's Fernando Alonso admits it is only a matter of time before Sebastian Vettel wins the world championship.

The Red Bull driver will clinch the title if he wins Sunday's Japanese GP with Alonso lower than eighth.

Alonso said the priority was protecting his and the team's second position in the drivers' and constructors' titles.

"If he doesn't win the championship here, he will do it in India or Abu Dhabi. It is not the most important point of the weekend," Alonso said.

"We will not race to try to finish in the top eight to try to keep the championship alive. We will race as hard as possible to try to finish ahead of the Mercedes. That is a very important goal for us.

"If we can keep the championship open until India it will be OK but it will not change too much for us. What we want to do is score as many points as possible."

Alonso is 77 points behind Vettel with a maximum of 125 still available in the remaining five races.

But he is only 28 ahead of Lotus's Kimi Raikkonen in third place in the championship, with Mercedes driver Lewis Hamilton a further six behind the Finn.

Ferrari are second to Red Bull in the constructors' championship, only one point ahead of Mercedes, with Lotus another 44 points adrift.

Alonso has qualified only eighth for the Japanese race, with team-mate Felipe Massa in fifth.

Hamilton and team-mate Nico Rosberg are third and sixth on the grid, with Lotus's Romain Grosjean fourth and Raikkonen ninth.

Alonso said: "It is more or less as expected. We were between seventh and ninth all weekend in all the free practice so we were expecting more or less to be in those positions.

"We would like to recover some positions in the race. Normally on Sunday we improve, yesterday in the long runs [in second practice, when the teams simulate race running] there were some good signs in terms of [tyre] degradation so we try to use that."