Fernandinho, who has five international caps, was not in Luiz Felipe Scolari's Brazil squad for last month's Confederations Cup which the hosts won with a 3-0 victory over Spain in the final.
Fernandinho: "It was very important for me (to be City's top close season target) and I want to repay the club for what they have done for me by playing well on the pitch and winning as many matches and as many trophies as possible.
"My first aim is to play well for my club Manchester City and if I do have good performances I'm sure that I will catch the attention of the national manager.
"The main challenge for me is the different style of play compared with my last team and also the amount of games you play throughout the season.
"It's much more than I was used to."