Nastasic, 19, said: "I am very happy to be in Manchester. I have seen only a small part of the city, but it looks a nice place to live and my team-mates have made me feel very welcome. They have told me I will have a good lifestyle in Manchester.
"Of course, Florence is very beautiful... but I am a professional footballer. I go where the challenge is biggest.
"I am not here to be a tourist. I have not arrived to walk around art galleries."