The Londoners tried to sign the 28-year-old from Shakhtar Donetsk but news of their interest never reached the player.
In any case he is happy at City and does not feel the need to try any harder on Sunday.
"It is not a case of showing my best just against Chelsea, it is about showing my best against all the teams," he said.
"We try to play good football to win all our games, that is no different whether it is against Chelsea or anyone else."
The same applies to him coming up against compatriots Oscar, Ramires and Willian as he does not see it as an audition for World Cup places.
"I don't know. It is the decision of the Brazilian national coach. I do my work here, try to do my best and if he selects me then I will be very happy," he added.
And on Chelsea's attempts to sign him in the summer, Fernandinho said: "It is a complicated story.
"There was contact before Manchester City came in for me but nobody told me about this in Shakhtar.
"I don't know what happened between Shakhtar and Chelsea but I'm very happy. I have no regrets.
"City's results show this. We try to play good football and in the last few games we have played good football and got good results."
After back-to-back wins over West Ham and CSKA Moscow, Fernandinho hopes they can carry that momentum into the crunch clash at Stamford Bridge.
"We will go to Chelsea with good confidence after the wins at West Ham and CSKA.
"We have three or four days to rest and recover so we will be good condition for the game on Sunday."