Milan: Fiorentina captain and Italy international Davide Astori died of a sudden illness at the age of 31 on Sunday, leaving Italian football in a state of shock.

Serie A postponed all of Sunday's matches, including the derby between AC Milan and Inter Milan, as Italian and European clubs and dozens of players sent messages of condolence and expressed their disbelief.

"Fiorentina is deeply upset to have to announce that its captain Davide Astori has passed away, victim of a sudden illness," said Fiorentina in a statement. "Due to the terrible and delicate situation, and above all for the respect of his family, an appeal is made to everyone's sensitivity."

Defender Astori, in his 10th Serie A season, was found dead in his hotel room in Udine, where Fiorentina had been due to face Udinese at the Dacia Arena later on Sunday.

The Fiorentina staff became worried when Astori, who was married with a daughter, did not join his teammates for breakfast at around 9.30 am local time, club spokesman Arturo Mastronardi said.

Astori, who made 289 top flight appearances, joined Fiorentina on loan in August 2015 and the club signed him outright one year later. He previously spent six seasons at Cagliari and one on loan at AS Roma. He made 14 appearances for Italy between 2012 and 2017 and was in the squad at the Confederations Cup in 2013 where Italy finished third.

Udine state prosecutor Antonio Di Nicolo was quoted by the ANSA news agency saying it was believed "that the player died from a cardiac arrest, the result of natural causes".

Former Italy Prime Minister Matteo Renzi was one of the first to pay tribute to the player. "<>It seems impossible. You've been one of the best sportspeople I've ever metFormer AS Roma playmaker Francesco Totti said he was "shocked, incredulous and speechless for this tragedy".

Cesare Prandelli, Astori's coach in most of his Italy games, said he was "deeply upset, I feel a great emptiness inside".

Giovanni Malago, the head of the Italian Olympic Committee and acting head of Serie A, said it was his duty to call off Sunday's matches, which he did at the request of the clubs.

"I have spoken to more than one doctor and I don't want to get involved in speculation," he said. "I believe that no doctor in the world can ever tell you that there is a foolproof remedy when it comes to the risk of sudden death."