The Uruguayan, who joined the Saints last summer, enjoyed a productive first season in the Premier League, leading to claims that a host of clubs were prepared to make a move for his services.
However, he told tuttomercatoweb.com: "There is a lot of talk about the transfer market but I think I'll stay at Southampton.
"I want to repay the trust of the club. I'm happy in England and I have always dreamed of playing in the Premier League.
"There has been talk in the past of interest from Fiorentina and they are a club that I like. But Southampton count on me a lot."
Fiorentina have been strongly linked with the 22-year-old.