Italy international defender Davide Astori has died just 31 in a hotel bedroom on the eve of an Italian Serie A match.
Astori, the Fiorentina team captain, was at the hotel before today's scheduled - but now cancelled - match with Udinese.
There was no immediate cause of death officially released but Italian media are blaming a heart attack.
The club said: "Fiorentina are profoundly shaken and forced to announce that their captain Davide Astori has died.
"For this terrible and delicate situation, and above all out of respect for his family, we appeal to the sensitivity of the media."
Astori was capped 14 times by Italy. He began his playing career at AC milan but could not break into the first team
In Cagliari he played 174 times and worked his way into the international squad.
He also spent a year at Roma and, in 2015 moved to Fiorentina.
On Instagram, Italian goalkeeping legend Gianluigi Buffon wrote: "You have a young wife and family who are suffering, but above all a little girl, who deserves to know that her father was in every way A GOOD PERSON... a TRULY GOOD PERSON...
"You were the best expression of an old-fashioned world, one that people have left behind, with values like altruism, elegance, politeness and respect towards others.
"Compliments genuinely, you were one of the best sporting figures I ever came up against.