Having signed an eight-year contract in a £106.8m transfer at the start of January 2023, Fernandez has naturally held down a starting role for much of his time at Stamford Bridge.
A total of 67 starts and seven substitute outings have been made in all competitions, the World Cup winner chipping in with seven goals and six assists.
However, Fernandez has recently dropped down to the substitutes' bench for Premier League fixtures, being restricted to 55 minutes across games against Liverpool and Newcastle United.
The 23-year-old has subsequently been starting matches in the Conference League and EFL Cup, an indication that he is no longer regarded as first choice by Maresca.
That move has coincided with Romeo Lavia returning to fitness to partner Moises Caicedo in the engine room.
'I cannot lose confidence in him'
Speaking to reporters at a press conference, Maresca was required to acknowledge a moment of frustration at a misplaced Fernandez pass versus Newcastle in Wednesday's EFL Cup tie.
The Italian insisted that he continues to have total faith in the Argentina international, hinting that the door remains open for a Premier League recall.
Maresca said: "I show frustration with Enzo? I show frustration will all of them. Don't only look at Enzo. I still trust Enzo.
"There is not any reason I can lose confidence in him. The reason he is not playing in the Premier League is because I take another decision but I have 100% confidence in him."
He added: "I like to say that we don't have an A team or B team. There are players that are fantastic players, but for me, we don't have indispensable players.
"If Cole [Palmer] is not playing, we are playing Joao [Felix] and if Nico [Jackson] isn't playing, we are playing Christo [Nkunku]. The reason why we change players is because all of them are good. Some of them are better than the rest but it doesn't mean they are always the ones that are going to play.
"You are looking for some different reasons for Enzo, but it's simple: he is not playing at the moment but we have so many games in the future so it does not mean he is not going to play."
What do Caicedo and Lavia offer?
Chelsea fans have been left encouraged by the new partnership of Caicedo and Lavia, with Maresca claiming that the pair bring a greater balance to his engine room.
He said: "First of all, it is a matter of balance. I think in this moment, Romeo and Moises they give us physicality, strength in the middle. This is why we fund the option of using Malo [Gusto] in the pocket.
"Otherwise, when we play with Enzo, it has to be Enzo and one between Moises and Romeo, and when Enzo move, we maybe struggle a little bit in the middle in terms of physicality.
"That is something in this moment that Moises and Romeo give us. It does not mean that, in one game, we can play with Joao or Cole in the pocket. It depends on the game."
Fernandez is expected to start on the substitutes' bench when Chelsea square off against Manchester United on Sunday afternoon.