UDINE, Italy — Fiorentina captain Davide Astori was found dead in his hotel room on Sunday at the age of 31 after a suspected cardiac arrest before an Italian league match.
The defender, who played 14 times for Italy’s national team, was discovered by Fiorentina staff when he failed to show up for breakfast at the hotel in Udine. Fiorentina’s game at Udinese in northeast Italy was called off, along with all fixtures in the country’s top two divisions.
Mr. Astori’s body was taken to the Santa Maria della Misericordia Hospital for an autopsy.
‘‘The belief is that the player died of a cardiac arrest by natural causes,’’ Udine prosecutor Antonio De Nicolo said. ‘‘It is strange that such a thing should happen to a professional who is so closely monitored without there being any warning signs.’’
Fiorentina said Mr. Astori, who had played for the club since 2015, was ‘‘hit by a sudden illness.’’ Club president Andrea Della Valle said Mr. Astori had been due to sign a new contract on Monday and that it would have tied him to the club ‘‘for life.’’
‘‘For this terrible and delicate situation, and above all out of respect for his family, we appeal to the sensitivity of everyone,’’ the team said in a statement.
Mr. Astori leaves his wife, Francesca Fioretti, and their 2-year-old daughter.
In Florence, fans attached scarves, flowers, and messages to the gates of the team’s stadium, while banners paying tribute to him were put up outside several other stadiums.
There was an outpouring of shocked reaction across the soccer world. The English Football Association said it plans to honor Mr. Astori when it hosts Italy at Wembley on March 27 in a friendly.
Genoa and Cagliari were preparing to play in Serie A’s early game when the players were told of Mr. Astori’s death. Several — many of whom had played with Mr. Astori for Italy — walked off in tears and, when the match was officially called off, a picture of Mr. Astori was shown on the giant screen, leading to applause throughout the stadium.
Cagliari coach Diego Lopez, who played and coached Mr. Astori at the Sardinian club, had to receive medical treatment after finding out the news.
Chelsea coach Antonio Conte, who coached Italy from 2014 to 2016, struggled to hold back the tears as he reacted to the death before a Premier League game at Manchester City.
‘‘This is a tragedy,’’ Conte said. ‘‘This news really hurt me and it’s very difficult in this moment to find the right words for the family. ... He was a great player, especially a fantastic guy.’’
Mr. Astori made his Italy debut in 2011 and played at the 2013 Confederations Cup in Brazil where he scored against Uruguay.
Mr. Astori started out in the Milan youth academy but never played a senior match for the Rossoneri, making his Serie A debut with Cagliari in 2008.