The 29-year-old has been linked with a move to Genoa in recent weeks.
He told his own website: “It has been a complicated summer for me.
“Fortunately, though, I can now just concentrate on Fiorentina and the Italian national squad, which I have just returned to with great pleasure and satisfaction.
“I want to send a message to the fans who have shown me their faith and affection in these past few weeks – I’m happy and honoured to still be wearing the Viola shirt.
“Despite all of the rumours and negotiations about me, I’m happy to stay in Florence for the people and the squad.
“The club’s silence has disappointed me a little, but I want to have a great season and I just can’t wait to start.”
