Spain captain Sergio Ramos is not thinking about quitting international duty following next year's World Cup in Russia.

The tournament is expected to be the final World Cup for the likes of Andres Iniesta, while Ramos' centre-back partner Gerard Pique has already signalled he will retire after the competition.

But Ramos, who has won two European Championships and the 2010 World Cup with his country, hinted he will look to play on regardless of how Spain perform in Russia, should they qualify.

"I think about things day by day," he told reporters on Friday ahead of a crunch clash with Italy in Madrid.

"I am not thinking that this will be my last World Cup, quite the opposite. As long as I am motivated and happy, I'll think about playing."

Joint Group G leaders Spain and Italy are locked together on 16 points, but with only top spot guaranteeing a place at the World Cup the nation that finishes second faces a play-off to qualify.

And Ramos called for Spain supporters to get behind his side and avoid whistling Pique, who has been targeted by fans in the past.

"What we're concerned about is that there's a place at the World Cup at stake and, above all, it's at a grand stadium like the Santiago Bernabeu," he said.

"This is one of the best fixtures you could watch. I am sure the supporters will be our greatest ally. They will help us.

"Pique has been an exemplary player for the Spanish national team. Whistles don't help anybody."

Spain will be without Diego Costa, however, as the striker has not played this season for Chelsea due to a stand-off with the Premier League champions over his desire to return to former club Atletico Madrid.

"I could say a thousand things on Diego Costa," Ramos added. "Every player plans his holidays and his life as he sees fit. I don't know about the matter [with Chelsea] so I can't say anything about that.

"I hope that if right now he has more time to rest then he can come back with the same attitude as ever."