Although the state of Cristiano Ronaldo and Karim Benzema’s fitness has claimed the majority of the attention in the last week, Real Madrid’s loss of Casemiro for Wednesday’s Champions League semi-final clash with Manchester City is potentially an even bigger blow.

Although it’s obvious the Spanish team needs to score tonight to advance and that a fit Ronaldo will play a major role in that quest, Casemiro’s absence could be just as telling at the other end of the field, where City’s task of grabbing a priceless away goal has suddenly become a lot easier.

For the work that he has done since being restored into the starting line-up by Zinedine Zidane, the dogged Brazilian midfielder has epitomised the phrase ‘unsung hero’ by acting as the glue which has held the team together.

After being initially overlooked by Zidane, Casemiro was drafted into the starting line-up immediately after his team delivered a limp and incoherent performance to lose the local derby at home to Atletico Madrid in La Liga on February 27.

They have not looked back, winning 12 of their 14 games, with eight clean sheets, since that dispiriting afternoon at the Bernabeu and, more importantly, looking like a much more convincing collective unit. Only once in this run have they conceded more than one goal in a game, and that was the 3-2 victory over Rayo Vallecano last month in which the Brazilian was suspended.

Casemiro’s athleticism, tough tackling, ability to read the game and selfless willingness to maintain a defensively disciplined position have provided greater protection to a previously exposed back four, while also giving attacking players more license to get forward without losing the team’s shape.

The best example was the Clasico victory at Barcelona, where Casemiro’s relentless pressing in front of his team’s defence was a significant factor in the home team’s inability to establish any attacking rhythm.

Let’s not exaggerate – Casemiro is not the best footballer at Real Madrid. Technically, he is probably the worst. But he has done the perfect job for the team in providing much-needed stability in the centre of the field.

Without him, they will have to find an alternative and there is no obvious solution because both Toni Kroos and Luka Modric are more vertical players who do not provide so much presence in defence.

Other potential replacements such as Mateo Kovacic, Isco and James Rodriguez are also very different performers, leaving Zidane scratching his head as he wonders how to compensate for the absence a player who has suddenly become fundamental to his plans.

In Casemiro, Madrid haven’t just lost one player; they’ve potentially lost one of the biggest keys to their whole system.