Rinaldi had been in the youth setup at Serie A side Atalanta since the age of 13, winning the U17 Scudetto and Supercoppa Italiana in 2016.
Atalanta wrote: "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 hearts of those who had the good fortune to meet you."
Rinaldi had been on loan at Serie D side Legnano
Image credit: Eurosport
Legnano said in an official statement on their website: "AC Legnano, the city and the entire football universe, at all levels, today live one of their most upsetting days. Andrea Rinaldi, our warrior, has left us.
An aneurysm snatched him in the prime of life, with a life ahead of him and with a career that promised bright goals. A sudden and shocking tragedy, impossible even to imagine.
Legnano chairman Giovanni Munafo added: "When Andrea came to training, he came first to greet me. This is a memory I will carry in my heart.
"An extraordinary boy, an example for everyone. On behalf of the club, I express my deepest condolences to the family. We are sure that Andrea, from up there, will be the usual warrior like always, who fought in the middle of the pitch to bring the Legnano fans joy."
Rinaldi - who had previous loan spells at Imolese and Mezzolara - made 23 appearances for Legnano this season, scoring one goal.