Fiorentina have retired the No 13 shirt formerly worn by captain Davide Astori following the death of the 31-year-old.
The Serie A club announced the gesture on Tuesday morning, while confirming Astori's former club Cagliari would also be taking the same action.
Astori died suddenly on Sunday morning in a Udine hotel, where La Viola were basing themselves ahead of Sunday's Serie A match against Udinese.
All Serie A games were postponed as a result and tributes from the world of football soon began to pour in for the player.
The cause of death was due to a suspected cardiac arrest by natural causes, a Udine prosecutor has said.
Italy legend Gianluigi Buffon was among those paying tribute to his former team-mate, taking to social media to write a lengthy and heartfelt message in Astori's memory.
Chelsea manager Antonio Conte, who selected Astori while manager of the Italian national team, has also spoken warmly of his former player.
"He was a fantastic guy - a great player but especially a fantastic guy. I stay very close to his family in this moment because he was only 31. It's very difficult to explain this situation," Conte told Sky Sports.
A minute's silence will be held before all Champions League games this week in tribute to Astori.