Matches canceled

Fiorentina's game was called off in the morning. The early kickoff between Genoa and Cagliari, one of Astori's former clubs, was canceled when players learned the news while warming up on the pitch.

The other five Serie A matches scheduled for Sunday, including the Milan derby, were also called off.

"Fiorentina is profoundly shocked to have to announce the death of captain Davide Astori after a sudden illness," the Florence-based club said on Twitter.

Astori died of "natural causes" after a "cardiac circulatory collapse" - a type of heart attack - Antonio de Nicolo, a Udine magistrate was quoted in Italian media as saying.

The magistrate added that it was "strange that such a thing happened without any warning symptoms in a profession that is so closely monitored".

Astori's body was taken to a hospital in Udine for an autopsy.

Astori began his career at AC Milan, also playing for Cagliari and Roma before joining Fiorentina in 2015. He played 14 times for Italy.

He made his international debut under coach Cesare Prandelli in March 2011 as a first-half substitute in a 2-0 victory over Ukraine in Kiev before getting sent off with 17 minutes remaining.