Mari left Monza this week before the Viola in an outright transfer.
He moves to Fiorentina for a reimbursement of € 1.8 million, where a deal is written until 2027 with the option for another 12 months.
Mari stated: “Thanks from the ground of my heart Monza for making me feel at home in these years.
“Wearing this shirt was an honor, I will always bring the memories and emotions that we have experienced together.
“Thanks to my teammates, the staff and fans for all support and great affection.
“Forever Biancorosso”.