Real Madrid lack the uniformity of shape in their tactical blueprint by design. The lopsidedness in Madrid’s formation is not forced, but intentional. It has been that way for years. Carlo Ancelotti’s use of Angel Di Maria as a left-attacking-midfielder in a traditional 4-3-3 in 2013-14 started this and the trend remained in some way or the other during Zinedine Zidane’s reign too. The lack of uniformity still exists. Real Madrid is a team that relies heavily on its left flank to produce high-quality chances. This is not necessarily a deficit as Madrid’s two best attackers- Karim Benzema and Vinicius Jr like dominating the left side.
On the other flank, Real Madrid do not really have an out-and-out/traditional right-winger across their roster (barring Marco Asensio perhaps). Their two best players on that wing are Fede Valverde — a midfielder turned winger — and Rodrygo, who was originally a left-winger at Santos. The Brazilian is still learning the ropes to become a fully reliable right-winger. The importance of a fully fit and in-form Dani Carvajal in this context is nothing less than paramount for Real Madrid.
Having two-equally powered full-backs is a safety net that no good team would say no to. Among Real Madrid’s European rivals, only Manchester City, Liverpool, PSG, and to some extent Bayern Munich, have fullbacks of similar defensive and offensive qualities on both their flanks. A few summers ago, Marcelo’s decline in form and health coincided with Carvajal's lingering health issues in a manner that Madrid hardly got restrained offensive support from their fullbacks for a large stretch of time.
Ferland Mendy’s arrival ensured defensive solidity on the left wing but even in his fourth season, Mendy has no chemistry with Vinicius Jr and the Frenchman has a concerning deficiency in attacking skills, especially in the opponent’s half.
This makes things complicated for Real Madrid. Since Mendy moved to Madrid, Carvajal trumps Mendy in p90 metrics of xG, xA, sh, passes into the penalty area, progressive passes, key passes, and passes into the final third. While Mendy marginally eclipses Carvajal in goal-creating actions.
Madrid have a lopsided tactical blueprint that is heavily reliant on the left flank but cannot use the full potential of the team there due to Mendy’s lack of synergy with Vinicius. On the other flank, the choice of the attacker often becomes match specific, hence, it is imperative that Real Madrid have someone as a rock back on the right, just like Dani Carvajal has been since the start of this season.
While Carvajal is still far away from his attacking best, his defensive work rate has been admirable. He has won the individual battles against some seriously dangerous left-wingers this season. His positioning and awareness have also helped the team in the first phase of build-up.
Carvajal's return to form was necessary and timely. This is going to be a long season. Carvajal is also going to be at the World Cup. Ancelotti has so far managed Carvajal’s workload really well, rotating him regularly with Lucas Vazquez, allowing Dani to recover. If he continues the form he is in right now, Ancelotti would have one less thing to worry about.