Dani Olmo believes Pedri is "indispensable" for Spain and backs the midfielder to bounce back from his performance against Portugal.

Spain reached the quarter-finals of the World Cup with a 1-0 win over Portugal, courtesy of Mikel Merino's stoppage-time winner.

Pedri failed to make his usual impact for Spain in the victory, struggling to penetrate Portugal's backline while only winning one of his five duels; he won five of his seven duels against Austria in the previous round.

Spain also scored their winner after Pedri was replaced late on, but Olmo defended his compatriot and Barcelona team-mate.

"Pedri is a spectacle to watch, to train, and to play," said Olmo. "Every time I see him, he's spectacular.

"With and without the ball, having him on the field, knowing Pedri is playing gives you an extra boost.

"He's a player we have to have and need on the pitch; he's indispensable for us."

Spain face Belgium for a place in the semi-final; they are unbeaten in their last 11 meetings with Belgium in all competitions (W9 D2) since a 1-2 defeat at Euro 1980.

Indeed, La Roja have won their last five games in a row against the Red Devils by an aggregate score of 13-1.

This will be Spain’s sixth World Cup quarter-final. After being eliminated from each of their first four from 1934 to 2002, La Roja won their last 1-0 against Paraguay in 2010 en route to lifting the trophy.

Luis de la Fuente's side could meet France in the last four, but Olmo refused to look past their clash with Belgium.

"We're only thinking about Belgium; it's the World Cup quarter-finals, and that's the priority," said Olmo.

"The quarter-finals come before the semi-finals.

"Belgium is a very complete team; they have the best goalkeeper in the world and are very tough. They have exceptional players who we have to be very careful with."