(CNN)Atalanta midfielder Andrea Rinaldi has died aged 19, the Italian club said in a statement on its website.
Rinaldi, who had been on loan at fourth-tier side A.C. Legnano, was described by Atalanta as a "positive" personality and "well-liked by everyone."
A.C. Legnano said in a statement on its website that Rinaldi's death had been caused by an aneurysm.
"In the prime of his years, with a life ahead and a career that promised bright goals ... sudden and shocking tragedy, impossible even to imagine," the club said.
In its statement, Serie A club Atalanta said: "Just as on the pitch you were always the last to surrender, this time too you fought with all your might not to fly away too soon.
"But that kind smile of yours will always remain alive in the heart of those who have had the good fortune to meet you."