"Fiorentina are profoundly shocked to have to announce the death of captain Davide Astori after a sudden illness," the Serie A club said on Twitter.
La Fiorentina profondamente sconvolta si trova costretta a comunicare che e' scomparso il suo capitano Davide Astori, colto da improvviso malore.
— ACF Fiorentina (@acffiorentina) March 4, 2018
Per la terribile e delicata situazione, e soprattutto per rispetto della sua famiglia si fa appello alla sensibilità di tutti. pic.twitter.com/bFGnkReWEC
The 31-year-old, who leaves behind a two-year-old daughter, was in Udine to prepare for Sunday's match against Udinese, which has been postponed according to reports.
The club called on the media to respect Astori's family in what it called a "terrible and delicate situation".