Real Madrid have made signing a new centre back 'a priority for next season' after failing with summer moves for a trio of defenders from rivals Barcelona and Atletico Madrid.
Los Blancos are keen to add to the heart of their defence because of a perceived lack of cover for key men Sergio Ramos and Raphael Varane.
Behind the Spanish and French stars in the pecking order are Nacho Fernandez and Jesus Vallejo. But the club are reportedly convinced they need to bring in 'another alternative'.
According to Marca, Real tried to solve the problem in the summer transfer window by signing one of Atletico's Jose Gimenez and Lucas Hernandez or Barcelona's Samuel Umtiti.
Those moves failed to come off though, with all three targets signing new contracts at their respective clubs.
Hernandez recently admitted he turned down the opportunity to move across the Spanish capital and join his brother Theo, who joined Real from Atletico in 2017.
The France international said he had paid the offer little heed out of loyalty to Atletico - but refused to rule out a potential transfer in the future.
Hernandez told French broadcaster RMC Sport: "I didn't pay too much attention. I was 100 per cent focused on my club, where I had recently signed a new contract."
"My agent told me about it. When he said there was an opportunity to go to Real Madrid, I told him I couldn't do that."
"Atletico are my club, a team who have given me everything. I'm an honest person and I couldn't go to Madrid."
"I hope I can stay here for a very long time, but football moves very fast. If an offer comes in that I can't refuse…"
Hernandez played all seven games for France at the World Cup as they lifted the trophy in Moscow, selected as Didier Deschamps' first choice left back.
Umtiti, who may now be out of action until 2019 if he undergoes knee surgery, was also a key player for the French in Russia, while Gimenez enjoyed a stellar tournament alongside his club colleague Diego Godin for Uruguay.