MADRID - Spanish players have said they are worried by the sudden death of Espanyol's Dani Jarque on the weekend and have called for an improvement in the screening for potential heart problems. Espanyol defender Jarque, 26, collapsed and died from a heart failure in his hotel room while on tour with his side in Italy on Saturday. His death came only two years after Sevilla midfielder Antonio Puerta, 22, collapsed during a game and later died after a prolonged cardiac arrest. Sevilla goalkeeper and captain Andres Palop, who witnessed first-hand the collapse of his former team-mate Puerta, offered his condolences to Jarque's family in a news conference on Monday. "It's a terrible loss. Once again it has been a young lad, with his life in front of him, and I would have preferred to never see it happen again. But here it is once more," he said. "It starts to worry you. We do tests and medicals but it isn't possible to detect these cases. We hope they will specialise a little more to try and improve the detection so that it doesn't happen again." After Puerta's death in 2007 doctors said the weakness in the player's heart was extremely difficult to detect and was unlikely to show up in medical tests. Spain and Real Madrid midfielder Ruben de la Red also collapsed during a match in October last year, but doctors have still not managed to find out why. The 24-year-old has not played a game since. "It's strange there are so many cases in such a short space of time. It makes you think it could happen to anyone," Villarreal midfielder Santi Cazorla told reporters as he joined up with the Spain squad on Monday. Liverpool and Spain winger Albert Riera added: "Of course it's something that concerns us. They say it isn't possible to predict these things, because normally there is no warning, with the exception of what happened to De la Red. "It is something they have to start to look at to see of there is some sort of solution." An autopsy was carried out on Jarque in Italy on Monday but the results are not yet available.