Portugal vs Spain: How can Roberto Martinez unlock La Roja's record-breaking World Cup defence in battle of Arlington

Spain head into Monday's 2026 World Cup last-16 meeting with Portugal boasting the tournament's best defensive record, having yet to concede a goal in four matches.

For Roberto Martinez and Portugal, the challenge is obvious if they are to advance: become the first team at this World Cup to breach a defence whose remarkable run has already secured its place in tournament history.

Ahead of this Round of 16 tie, Sports Mole looks at how Portugal can become the first team to breach Spain's defence at the 2026 World Cup.

Unai Simon leading Spain's defensive masterclass

The numbers underline just how difficult Spain have been to break down, with goalkeeper Unai Simon having now gone 519 consecutive World Cup minutes without conceding, surpassing the record of 517 minutes previously held by Italy's Walter Zenga since 1990.

Spain have recorded clean sheets against Cape Verde, Saudi Arabia, Uruguay and Austria, while Pau Cubarsi has continued to mature alongside Aymeric Laporte in one of the tournament's most composed central defensive pairings, with Pedro Porro and new Real Madrid signing Marc Cucurella providing protection from the full-back positions.

The balance throughout Luis de la Fuente's side has arguably been just as important, with Rodri shielding the back four and allowing Spain to dominate possession, limiting opponents to very few meaningful chances.

In the 3-0 round of 32 win over Austria, Spain became the first team since Germany in the 2014 final to not allow a single shot on target in a World Cup knockout match, highlighting just how dominant they have been defensively.

Spain have defensive weaknesses and Portugal can expose them

Martinez's side came from behind to beat Croatia 2-1 in the Round of 32, with Cristiano Ronaldo scoring his first World Cup knockout goal from the penalty spot before Goncalo Ramos struck the stoppage-time winner with a header, showing the depth they possess.

While Spain deserve enormous credit for their defensive record, it must be noted that they have not faced an attack with Portugal's variety.

Ronaldo, Ramos, Rafael Leao and Bruno Fernandes each offer different qualities in the final third, while Nuno Mendes provides an additional attacking outlet with his surging runs from deep.

As seen in their penalty shoot-out triumph over Spain in the UEFA Nations League, Portugal can hurt Spain on the counter-attack, particularly with runners in behind given how high De la Fuente's side like to defend, and once again,

Martinez must resist trying to dominate possession against a side that thrives with the ball.

Instead, Selecao das Quinas may enjoy greater success attacking quickly after turnovers, particularly into the spaces vacated by Spain's adventurous full-backs.

Another potential route to goal will be dead-ball situations, as Spain have rarely been tested from set pieces, and with Portugal possessing two outstanding aerial threats in Ronaldo and Ramos, they could cause some problems.

Ramos or Ronaldo remains Martinez's biggest decision

Heading into this clash, Martinez's biggest selection dilemma remains who should lead the line.

Ronaldo answered some of his critics by scoring against Croatia, although Portugal looked more dynamic after Ramos entered the contest and eventually settled the tie.

Ramos offers greater mobility and pressing intensity, making him well suited to stretching Spain's defensive line, whereas Ronaldo remains one of football's finest penalty-box finishers and brings unmatched experience on the biggest stage.

Whether Martinez opts for Ramos' movement or Ronaldo's finishing instinct could prove decisive against a Spain side that has yet to give any opponent a clear route through its record-breaking defence.