The Serb was sold by the Viola last week.
He posted to social media:
"Florence, 7 years old, unforgettable trip.
"You, who welcomed me from day one as if I were your son.
"You, who gave me the opportunity.
"You, who made me grow.
"You, who have become my second home.
"You, who saw me as a child and now accompany me like a man.
"You, who gave me the greatest emotions.
"You, who gave me unforgettable memories.
"You, who allowed me to dream and make those dreams come true.
"You, who have always supported me.
"You, who have always loved me.
"You, who have always been by my side.
"You, who have always pushed me.
"You, who were my greatest motivation.
"You, who rejoiced and cried together with me.
"You, who deserve successes and trophies.
"You, who have made the impossible possible with your support.
"You, who made every match hell for your opponents.
"You, who have been my pride and my privilege.
"You, who were my family.
"I gave you everything. I gave you everything.
"You gave me everything. You gave me everything.
"You got under my skin, right into my heart.
"Florence, an eternal love that will remain there forever.
"A huge THANK YOU, to you, to you, to my teammates, to the whole club, President, Directors, Coaches, Staff and all the people who make this club special every day. Yours Nikola."