The Argentina World Cup winner arrived for £106.8million with great hope in January but is yet to produce his best at Stamford Bridge and his form is waning as the Blues toil.
Fernandez remains a key player for Chelsea but he has been substituted by Mauricio Pochettino in their past two games due to his lack of impact.
He was withdrawn after 68 minutes in Sunday’s 1-0 defeat by Aston Villa. That followed another tired 81 minutes in a 0-0 draw at Bournemouth after the international break.
Fernandez had just travelled back from a match against Bolivia in the altitude of La Paz but Pochettino has been forced to keep playing him due to the injury crisis at Chelsea.
The midfielder has shown his quality in spells since his move to London but he has failed to make a single key pass in those two matches since his return from Argentina duty.
His recent switch to the No10 position has highlighted his deficiencies. Fernandez has lacked any goal threat, his only Chelsea goal so far coming against League Two side AFC Wimbledon in the Carabao Cup. He is now on the ball less and focusing on both pressing and running in behind, two tasks outside his usual remit.
Pochettino’s decision to push him forward is increasingly being met with criticism.
Injuries to Christopher Nkunku and Carney Chukwuemeka have forced the head coach to turn away from the partnership between Fernandez and £115m signing Moises Caicedo deeper in midfield.
Cole Palmer is another option to play as the No10 but so far he has not been deemed ready, though he is set to start against Brighton in the Carabao Cup tomorrow.
Fernandez showed at the World Cup that he is a class act and his decline is an inevitable symptom of the problems around him.
The injury crisis at Stamford Bridge cannot be underestimated. It has forced Fernandez, Ben Chilwell and Levi Colwill to play out of position and disrupted cohesion after a good pre-season.
Confidence is draining from the youngest squad in the league.
Only Manchester City have enjoyed more possession, passes and touches than Chelsea this season but a lack of goals and mistakes at the back are costing them.
Nicolas Jackson has struggled since his £31m summer move and is banned for Monday’s trip to Fulham after picking up his fifth yellow card of the season against Villa.
Losing £58m summer signing Christopher Nkunku to a knee injury in pre-season was a major blow. Pochettino wanted to build his attack around Nkunku but he is expected to be out until December.
Pochettino has another headache at right-back, with Malo Gusto banned for three games for his red card against Villa and Reece James sidelined through injury.
Chelsea, 14th in the Premier League and already nine points outside the top four, were booed off again against Villa and supporters are growing frustrated with the “project” of owners Todd Boehly and Clearlake.
Champions League qualification already seems a long shot this season and there looks set to be some serious short-term pain in the plan to get Chelsea to the top of English football.
Tomorrow’s game against Brighton is a chance to help lift the mood ahead of a testing run of Premier League games, with Arsenal, Tottenham, Manchester City, Newcastle, Brighton and Manchester United among the opponents in Chelsea’s next nine fixtures. But the concern is that losing is becoming a habit, even for a World Cup winner like Fernandez.