Spain's Luis de la Fuente, head coach of the national football team, heaped praise on his substitute Mikel Merino, who scored the winning goal against Portugal 1-0 on Monday evening in the Round of 16 of the World Cup, just six minutes after coming on. During a press conference after qualifying for the quarter-finals, De la Fuente said: 'Merino never disappoints.' He added: 'He is a guaranteed value. He gave us the European Cup, and in decisive moments he is always present. He is among the best in the world in his position,' and mentioned that some of his team's substitutes would be starters for any other team. De la Fuente reiterated his view that the match against Portugal was an 'early final,' and commented on its proceedings: 'As expected, we suffered until the end. We played a very complete game.' He noted that his young winger Lamine Yamal played one of the most important matches of his life, explaining: 'Apart from his brilliance, it is one of those matches that will greatly help him continue to develop.' He added: 'Nuno Mendes' injury may have been due to the intensity of defending against Lamine. Today he suffered for the team and created a lot of danger.' Spain reached their first quarter-final since winning the 2010 World Cup in South Africa, achieving a record of six consecutive matches without conceding a goal in the global event. The coach commented: 'This record is a result of the team's work. We have great defensive solidity thanks to solidarity, sacrifice, and team spirit, and that is what makes us strong defensively.'