(Photo credit: Daniel Becerril-Reuters via Imagn Images)

Mikel Merino is relishing Spain's opportunity to advance to the semifinals of the World Cup, although first up is a quarterfinal matchup against Belgium in Inglewood, Calif., on Friday.

Merino played a major role as Spain stayed alive with his stoppage-time goal in a 1-0 win against Portugal in the round of 16 on Monday. And yet the clutch goal is but one reason the midfielder is appreciative of the moment at hand.

Merino nearly missed his World Cup opportunity after a stress fracture and subsequent surgery in late January put his roster spot in doubt. Despite the Arsenal midfielder playing fewer than 30 minutes in the months leading into the World Cup, Spain coach Luis de la Fuente had no doubt about Merino's status.

'I have a great affection for all the players, but with Mikel Merino there's something special because we've known each other for a long time,' de la Fuente said. 'If necessary, I'd go to pick him up at his house. He's world-class.'

The unwavering confidence shown by de la Fuente was rewarded when Merino came off the bench and stepped up during a crucial moment in the 85th minute to score the winner.

'Life has its ups and downs, good times and bad,' Merino said. 'When they told me about the injury, I thought I wouldn't be at the World Cup and here we are. ... The fact of being here a few months ago was unthinkable.'

His late heroics give a chance for Spain's impenetrable defense to be tested against Belgium, who toyed with the United States in a 4-1 win on Monday at Seattle as Charles De Ketelaere scored twice.

Spain goalkeeper Unai Simon has not conceded a goal in five matches, while extending his scoreless streak to 609 minutes. But Belgium eased past the Americans while resting midfielder Kevin De Bruyne and not using forward Jeremy Doku until the 67th minute.

With a desire to seal the victory in emphatic fashion, Belgium coach Rudi Garcia brought in super sub Romelu Lukaku to score his third goal of the tournament.

'I think all the players picked by the gaffer (coach) did a great job and that just goes to show the strength of our squad,' Belgium captain Youri Tielemans said. 'We want to keep performing and win our next match too, but we know Spain will be very tough to beat.'

Tielemans exemplified the all-in approach when Garcia tabbed him for a one-time move into De Bruyne's attacking midfielder position.

'It was a different role for me,' Tielemans said. 'I was higher up the pitch, which suits me well. I try to be the best player I can be on every position I need to play to help the team and lead us out there.'

Belgium move forward without midfielder Amadou Onana, who went down with an anterior cruciate ligament injury early against the United States, bringing an end to his World Cup.

The winner Friday will advance to Tuesday's semifinal against the winner of the quarterfinal match between France and Morocco at Foxborough, Mass., on Thursday. From what he has witnessed in the tournament, de la Fuente likes his team's chances of being in the semis.

'We have many qualities that will make our opponents think we're the team to beat,' de la Fuente said. 'We have a lot of confidence in ourselves, we're very sure of ourselves, and we'll give our best until the very last moment. Our opponents will have to beat us.'

--Field Level Media