The midfielder says it is too early to talk about the title race or rule out struggling Chelsea.
The midfielder suffered a thigh injury towards the end of last campaign that has so far kept him out of the City team this term, although he returned to the bench for the midweek Champions League loss to Juventus.
It has been a frustrating period for the former Porto man, as the Manchester City side have started the season on fire without him, winning all of their goals and keeping a clean sheet in all of their games so far.
And he says he will come back stronger and help the side, praising the concentration they have shown to be on maximum points this season.
"I am going to come back stronger than ever," he told Sky Sports.
"Concentration has been very good which is why we've been able to score and not concede any goals. We need to keep working very hard every day to maintain the run of victories."
Too early to discuss the title race
As already mentioned, City have started the season on fire after a disappointing campaign last year saw them fail to defend their Premier League title.
Their impressive start, which has also included a highly accomplished 3-0 win over Chelsea, has got many now predicting that they could run away with the league this season.
Fernando, though, says it is much too early to talk about the title race and that Manchester City cannot rule Chelsea out just yet.
"It's way too early to speak about the title race," he added.
"All of the big clubs here in England sooner or later end up being in the title race. It is a very difficult and long season. We cannot rule Chelsea out yet and they can make up the points they've already lost."