The European champions brought in Denzel Dumfries, Marc Cucurella and Ibrahima Konaté over the summer, and kept hold of Raúl Asencio as cover, yet there remains a sense inside the Santiago Bernabéu that the squad is still one central defender short of what José Mourinho would consider ideal.
According to reports from Graeme Bailey, Real Madrid are keeping a close watch on the 24-year-old Englishman's progress at Goodison Park, though any move is complicated by Everton's refusal to sell.
Everton have reportedly placed a €93 million valuation on Branthwaite, reflecting both his importance to David Moyes' side and the premium attached to young, homegrown Premier League talent.
His fitness record remains a point of consideration for any suitor — recurring hamstring problems limited him to missing 31 matches across all competitions last season — though he has started the current campaign in excellent form, with those issues now appearing to be behind him.
Real Madrid are far from alone in their admiration. Manchester United have long been keen on Branthwaite and are reportedly ready to reignite their interest to strengthen Michael Carrick's defence.
Former Manchester United chief scout Mick Brown confirmed the club's ongoing interest, saying: "Branthwaite is somebody who has been high on their list for a long time." Manchester City and Atlético Madrid have also been mentioned as potential suitors, should Everton's asking price become more manageable.
For now, Everton's stance shows no sign of softening, with the club's resistance to selling one of their key defensive assets only reinforced by the level of competition already circling for his signature.
Branthwaite has been a regular fixture in Everton's defence since establishing himself as a first-team player, having progressed through spells on loan at PSV Eindhoven and Blackburn Rovers before nailing down a starting role at Goodison Park.
His performances have also made him a fixture in England's senior squad in recent seasons, further underlining the profile that has attracted interest from some of Europe's biggest clubs. With his contract running until 2030, Everton are under no pressure to sell before they are ready, giving them significant leverage in any negotiations that do eventually take place.