Top names from AC Milan, Inter and Juventus are among those who have paid their respects to the ex-Italy Under-21 international, who sadly passed away on Saturday
Mauricio Isla was a former team-mate of the 25-year-old at Udinese between 2009 and 2012, and he used Twitter to post a message of remembrance to his ex-colleague.
"Piermario will be remembered as a great friend and a great person. You're the greatest of all."
Meanwhile, Juventus and Italy midfielder Claudio Marchisio took to his official Facebook page, saying: "I do not know what to say, I think of a him as a friend and a colleague.
"I did not know him very well, but I can say he was an amazing guy.
"I encountered him often at youth level when I was with Juventus and he was at Atalanta, and also with the Under-21s! We'll miss you so much Piermario."
AC Milan vice-president Adriano Galliani told Sky Sport Italia: "It is terrible news, I do not know what to say.
"When faced with death, you cannot talk about football."
Javier Zanetti was also quick to pay tribute to the midfielder, saying that his Inter team-mates were all deeply affected by the news.
"We are all very upset about what happened to Morosini. We're all deeply saddened and are extremely sorry," he told the club's official website.
"Something unbelievable has happened, and it was clearly the right decision to postpone all of the league games.
"On behalf of my team-mates, our thoughts and sympathies go out to his loved ones."
Palermo goalkeeper Emiliano Viviano was equally as stunned by the news, and left a brief message on Twitter as a mark of respect for Morosini.
"I am shocked and speechless. Rest in peace Piermario."
Morosini made 18 appearances for the Azzurrini and was part of Pierluigi Casiraghi's 23-man squad for the 2009 European Championships. He also represented Bologna, Vicenza, Reggina and Padova during various loan spells.