MADRID - Spain sent out a warning to their World Cup rivals as Isco grabbed a hat-trick in a 6-1 thrashing of Argentina, who were missing the injured Lionel Messi, in a friendly on Tuesday. On what was supposed to be a historic night for Argentina captain Javier Mascherano, who joined Javier Zanetti on 142 caps as his country’s record appearance holder, things quickly turned sour as Diego Costa, Thiago and Iago Aspas also found the net. It will have made uneasy viewing for coach Jorge Sampaoli and emphasised more than ever how reliant his side are on their talisman Messi, who has been struggling with a muscle problem. Should the Barcelona forward be missing at any point during this year’s finals in Russia, Argentina are likely to struggle judging by their meek surrender in the Spanish capital. Without Messi on the pitch there was room for someone to take the game by the scruff of the neck and Real Madrid’s outstanding Isco filled the void. The diminutive midfielder dictated play from the centre of the pitch throughout as Spain ruthlessly and consistently exploited the high Argentine defensive line. “I’m not going to discover anything else about how much I like Isco and having him here with us,” Spain coach Julen Lopetegui said. “We’ve beaten a team with a strong history who got to the final of the last World Cup. Obviously, once we’re there you start from scratch and they had a couple of important absentees but we’re happy – it’s a real match and a deserved win.” Argentina might have taken the lead in the opening five minutes, but striker Gonzalo Higuain volleyed wide from close range which was an omen of things to come. Costa then bravely prodded in from close range after 12 minutes, despite being clattered by goalkeeper Sergio Romero. Both players required lengthy treatment and eventually left the pitch at different stages. Romero’s replacement, Chelsea back-up Willy Caballero, who starred in Friday’s 2-0 win over Italy, suffered a nightmare. A wayward pass with his first touch saw Isco gleefully sweep home Spain’s second in the 27th as they threatened to run riot. Defender Nicolas Otamendi briefly offered the visitors hope as he towered above the defence to nod in before the break. But after the restart it was again all Spain with haphazard goalkeeping and defending all contributing to a procession for the former world champions, who condemned Argentina to their heaviest defeat since a 2009 loss by the same score to Bolivia. Spain face European champions and Iberian rivals Portugal as well as Iran and Morocco in Group B at the World Cup, while Argentina will play Iceland, Croatia and Nigeria in Group D. Agencies