The Italian Under-21 international will cost Viola around £7million.
Canini has been struggling with a knee ligament injury and played just four Serie A games last term.
His agent Renzo Contratto said: “I have to admit that negotiations are already taking place. However, nothing has been decided just yet.
“Nevertheless, there is no doubt at all that Florence is at the top of my client’s wish list when it comes to possible destinations.”