The former Manchester United has been outstanding with Fiorentina this season.
Asked about next term, De Gea told La Repubblica: "I have signed for a year and the club has the option to renew.
"I am happy in Florence, I am happy to be at Fiorentina, but first it is important to finish the season in the best possible way.
"The city is splendid, the people wonderful. The club has a unique history, the Franchi excites me, I find it beautiful and very warm. I immediately said yes. And then, the Italian championship has always attracted me."
De Gea also said of his year out of the game: "After playing for so many years at the highest levels, I just wanted to be a bit calm. Perhaps it was the best period of my life. I was able to live intensely with my family, my wife Edurne, my daughter Yanay, see more often those friends that I had managed to see so little in recent years.
"I moved from Madrid to Manchester and continued to train my mind and body."