According to AS, the Real Madrid manager is eager to add a dynamic box-to-box presence to his squad despite already securing the signings of Bernardo Silva, Marc Cucurella and Ibrahima Konate.
The Spanish giants are believed to view Fernandez as the ideal candidate to strengthen the centre of the park.
The Argentina international, 25, arrived at Chelsea in 2023 in a 105 million-pound move and remains tied to the Premier League club until 2032.
Any attempt to lure him away from Stamford Bridge is expected to be costly, with Chelsea reportedly seeking in excess of 100 million pounds for the midfielder.
Should a deal for Fernandez prove difficult, Madrid have also identified Mateus Fernandes as a potential alternative.
The midfielder is valued at around 80 million pounds and has attracted interest from Manchester United as well. His connection to Mourinho could prove significant, as the pair are represented by the same agent.
While midfield recruitment remains a priority, AS reports that Mourinho is also looking to bolster his defensive options ahead of the new campaign.
Central defence is another area under consideration, with Manchester City defender Ruben Dias said to be among the names being assessed.
