Rivera has been left unimpressed by owner Gerry Cardinale, who has just overseen the dismissal of coach Sergio Conceicao and brought back Max Allegri.
He told Libero: "The Americans still don't know much about football. They even sent Paolo Maldini away. Why has he never taken me into consideration?
"Maybe I was a nuisance because I never kept the words my brain was thinking in my mouth!"
On teenage striker Francesco Camarda being left on the bench last season, Rivera, who made his pro debut with Alessandria at 15, also snapped: "Today it would be impossible to field a 15-year-old, at least here in Italy.
"You don't see Rivera, (Francesco) Totti and (Alessandro) Del Piero anymore because they don't play. They are there but the agents are in charge, they only do their own good. And sometimes the harm of football."