The Brazilian agreed to join the Premier League outfit earlier this summer from Ukrainian side Shakhtar Donetsk in a deal thought to be worth around £34m.
Looking ahead, the 28-year-old has conceded that he will have to adapt to a "different style", as well as a longer campaign.
"I think that was very important for me and I want to repay the club for what they have done for me by playing well on the pitch and winning as many trophies as possible," he told reporters.
"I think the main challenge for me is a different style compared with my last team and the amount of games during the season is more than I am used to."
Fernandinho has made five appearances for the Brazilian national team.