City boss Pep Guardiola admits he is unlikely to move the Brazilian back into midfield because he has adapted to playing in the back four so well.
With City light on central defenders after the departure of Vincent Kompany, the 34-year-old was pressed into emergency action at the back earlier this season due to injuries to Aymeric Laporte and John Stones.
Stones returned to action last month but Fernandinho has remained at centre-back, partnering either the England international or Nicolas Otamendi.
His ability in the role was evident on Saturday in a commanding display as City came from behind to beat Chelsea 2-1 in the Premier League.
#City were criticised after their loss at Liverpool a fortnight ago, with suggestions Fernandinho's presence was being missed in midfield, but Guardiola seems unlikely to change things.
"If Rodri and (Ilkay) Gunodgan are fit, I don't think so," said the City boss.
"I like Fernandinho in that position. With the problems we have I like it. I know he can play (in midfield) but we have Gundogan, and I trust him a lot, and Rodri."
Guardiola was impressed by Fernandinho at Anfield but feels he did not get the credit he deserved because of the result.
The champions lost the top-of-the-table clash 3-1.
A sarcastic Guardiola said: "If we lose he plays s**t. I know that. In Anfield he was the best central defender we played there, in the back four. He played a disaster. I know how this job works. But he was incredible in Anfield, he was incredible on Saturday."
Expanding on the theme of criticism, Guardiola feels the team as a whole have been harshly treated over their performances this term.
City, who clocked up a record 100 points in their 2018 title win and won a domestic treble last season, have lost three of their opening 13 Premier League games.
They are third and trail leaders Liverpool by nine points.
Guardiola said: "It looks like, if we won the last two Premier Leagues, we have to win seven Premier Leagues in a row and we have to make 200 points every season. It doesn't work in that way in the high, high level."