|Daniel Jarque in action against Liverpool last week [GALLO/GETTY]
Espanyol captain Daniel Jarque died of heart failure in his team's hotel on the eve of a friendly against Bologna in Italy.
He was 26.
Bologna said the central defender was found unconscious in his hotel room on Saturday night and was taken to a hospital, but "it was not possible to save his life.''
Espanyol said on its website that Jarque failed to respond to several attempts to resuscitate him.
"The doctor carried out CPR on the player and used a defibrillator, which showed that the arrest was non-responsive,'' Espanyol said.
"After a few minutes, the first ambulance arrived from the Florence emergency services, who tried again with the defibrillator they carried.
"The medical services continued carrying out CPR, administering adrenaline and atropine for an hour. But the player's heart did not react, so finally that determined his death.''
Italian sports daily Gazzetta dello Sport said Jarque was on the phone with his girlfriend when he suddenly fell silent and the woman then alerted club officials.
Espanyol are on a pre-season training camp and had earlier held a practice session in Coverciano, a suburb of Florence.
Sunday's match against Bologna has been cancelled and the team will fly back to Barcelona.
Arsenal and Valencia held a minute's silence in the middle of their pre-season friendly at Mestalla stadium Saturday night.
Jarque joined Espanyol at the age of 12, making his debut in 2002 and being part of the team that won the Copa del Rey in 2006.
Last month, Jarque was given the club captaincy. He also helped Spain win the European under-19 championship in 2003.
Barcelona and Real Madrid, both on tour in the United States, sent their respect.
"That such a young man, a great professional and sportsman, has suffered this has left us very upset. From here, our sincerest condolences,'' Raul told sports daily Marca.
Barcelona will wear black armbands in their match on Sunday against Chivas in San Francisco.
"We are greatly dismayed by this tragic event and we deeply regret it,'' Barcelona president Joan Laporta said.
Other players who have died of heart failure include Cameroon midfielder Marc-Vivien Foe, Sevilla midfielder Antonio Puerta and Motherwell midfielder Phil O'Donnell.
Foe died during a 2003 Confederations Cup semi-final against Colombia at age 28. He was later discovered to have had a heart condition.
Puerta collapsed during a 2007 league game against Getafe and died three days later following a prolonged cardiac arrest at age 22.
O'Donnell died after collapsing during a 2007 match against Dundee United in the Scottish league at the age of 35. An autopsy revealed he had died of heart failure.