If Lionel Messi and Argentina are to win back-to-back World Cup titles on Sunday against Spain, they will need to find a way through one of the toughest defenses in tournament history.

Spain's journey to the final in East Rutherford has been a triumph of collective spirit, with every component of coach Luis de la Fuente's well-oiled machine contributing.

But while the smooth midfield control of Rodri, Dani Olmo, Pedri, and Fabián Ruiz has grabbed headlines, the foundation of Spain's success has been the defensive line.

The back four—left-back Marc Cucurella, newly signed by Real Madrid; center-backs Aymeric Laporte and Pau Cubarsí; right-back Pedro Porro; with goalkeeper Unai Simón behind them—have conceded just one goal in seven matches.

Another clean sheet at MetLife Stadium on Sunday would give Spain the record for fewest goals conceded in a successful World Cup campaign, currently two goals shared by France (1998), Italy (2006), and Spain (2010).

Cucurella (27), who made his name in the Premier League with Brighton and Chelsea before completing his move to Madrid last month, takes pride in Spain's defensive record.

He said earlier in the tournament: 'The great teams are the ones that impose their dominance in both penalty areas.'

He added: 'Obviously, the fewer goals you concede, the more chances you have to win. We hope to continue this approach; if we defend well, we'll be closer to victory.'

Cucurella's tireless activity on the flank is complemented by the skill of Spain's dominant center-back duo: veteran Aymeric Laporte (32) of Athletic Bilbao and up-and-coming Barcelona talent Pau Cubarsí (19).

A wonderful player

Laporte, born in France and who spent six seasons with Manchester City under Pep Guardiola, has expressed great admiration for his young teammate.

He said earlier in the tournament: 'He's a wonderful player. At 19, he has already played a lot of matches for Barcelona and the national team. Time will tell a lot, but he has real quality.'

For his part, Cubarsí has shown no signs of youthful nerves on the biggest stage in world football.

His only blemish in the World Cup so far was allowing Charles De Ketelaere to score a header in the 2-1 win over Belgium in the quarterfinals.

Cubarsí said: 'I like to have a strong presence and play aggressively. I like to assert myself because in this position you can't back down from anyone. You can't let yourself be taken out of the game, and above all you need that personality to be decisive.'

Laporte has become one of Spain coach De la Fuente's most trusted assistants during the World Cup, thanks to his confident presence in the heart of defense, where he often serves as the launch point for Spanish attacks.

De la Fuente said: 'He is one of the defenders who best executes our philosophy. It's a luxury to have him in our ranks. He gives us great quality in distribution, passes the ball between the lines, and has true leadership personality. He's a very complete player.'

The other member of Spain's back four, Porro, has been the surprise of the tournament.

After being left out of Spain's Euro 2024-winning squad, Porro entered the World Cup following a very difficult season with Tottenham, where the club nearly got relegated from the Premier League.

But in North America, Porro has been superb both defensively and offensively, scoring a fine second goal in the 2-0 win over France.

Porro now dreams of emulating his heroes from Spain's 2010 World Cup-winning squad.

He said: 'In 2010, when we won the title, I was playing in the town square. That tournament... it was exceptional, especially the way it united the country. It would be amazing to repeat that.'