The former Spain and Manchester United No1 has been outstanding for the Viola this season.
Prade told AS: “We were good and quick to take advantage of an opportunity, everything lasted very little. David had many offers, but the desire to play in Serie A and in a city like Florence made the difference.
"We, the board and the coach, wanted to close everything very quickly and the president Rocco Commisso gave his approval, speeding up the process.
“The year of inactivity was true, but there was no doubt about his technical abilities and his human qualities . We knew that David had never stopped training and we were calm.
“A champion, on and off the pitch. A leader and an example. His contribution on the pitch is obvious, but his dedication in each training session is helping the group to grow and also overcome the most difficult situations."
Prade added, “Spain has some great goalkeepers and (Luis) De La Fuente has many options to choose from . I don’t know their hierarchies, but if there is an opportunity for David to go with the national team, Spanish fans can rest assured about who will protect his goal."