The Argentina international traded the Stadio San Paolo for the Liberty Stadium last month as part of a significant rebuilding project undertaken by Swansea manager Garry Monk.
Fernandez has yet to make his debut for the Welsh club but is excited by the prospect of playing for a side with whom he expects to fit in well.
"I have learned a lot from playing in Argentina and in Italy, and now I want to learn even more in the Premier League," Fernandez told Swansea's Jack Magazine.
"It has always been a dream for me to move to the Premier League, and I am so happy to have achieved that dream. I want to stay at this level because I believe it is the top level in the world right now.
"It is a great new challenge for me. Teams here are very ambitious. Even when sides are three goals up, they continue to push to score more. In Italy, if you are three up, the idea is to defend that lead.
"Although I didn't play against Swansea for Napoli in the Europa League last season, I saw a team that holds the ball and plays very good football. It caught my attention.
"I can identify myself with the Swansea style – I like to play the ball from the back and, of course, I love to defend too.
"I am looking forward to playing my first game in the Premier League, and I will be doing my best on and off the pitch for the supporters."
