Elia Longarini was playing for the town’s under-14s team alongside his brother, 13, when he began to feel ill and asked to be substituted.
A few minutes later he collapsed and died in front of his mother, who watched all of his games, the newspaper said.
An autopsy to determine the cause of his death is now underway.
Matteo Mogetta, a spokesman for the club, said Longarini was certified as fit to play after undergoing the necessary medical tests.
"There were two doctors there and a functioning defibrilator was on the pitch. Unfortunately, the unthinkable happened."
The club’s president, Matteo Medori, said: “I am shocked. I can only say that we are closely supporting the boy’s family,” while adding that "great attention" is paid to the club’s athletes, both in terms of facilities and medical procedures.
"But what happened today will reopen the debate on the greater prevention of risks related to congenital illnesses that are difficult to diagnose."