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One of the most extraordinary elements of Carlo Ancelotti's first 18 months at Real Madrid has been his ability to continually restructure the midfield.

Former coach Jose Mourinho relied on a double pivot of Xabi Alonso and Sami Khedira, whilst gradually introducing Luka Modric after his transfer from Tottenham Hotspur.

When Ancelotti arrived at the club, he was initially without Alonso, and then when he returned, he lost Khedira for a substantial period.

A three-man midfield of Angel Di Maria, Modric and Alonso provided the axis from which Los Blancos won the Champions League.

In the summer, Di Maria left for Manchester United and Alonso departed for Bayern Munich, with Toni Kroos heading in the opposite direction from the Bavarians.

The German had been one of his country's standout players as they claimed the World Cup crown in Brazil.

Kroos had also enjoyed a successful season with Bayern and formed an impressive partnership with compatriot Bastian Schweinsteiger.

At the Bernabeu, Kroos has adapted perfectly and has quickly become the linchpin to their midfield area.

Unlike many of his peers, Kroos could be described as a complete midfielder due to his all-round capability.

Initially there were concerns over his utilisation alongside Modric, as neither player is particularly defensive-minded.

However, it hasn't proved to be a problem with the two forming a mutual understanding in regard to who ventures forward.

At times Ancelotti has used a 4-4-2 formation with the wide men positioned very narrow when out of possession.

This has enabled the likes of Isco, Gareth Bale and James Rodriguez to assist with the defensive duties, whilst ensuring the team's less exposed in transition.

More often than not, it's Kroos who sits the deeper of the two central midfielders, as he looks to start attacks from in front of his own defence.

Kroos has the attributes to combine technical ability with natural strength, which makes him effective in both an attacking and defensive sense.

It's startling how much the club now relies on the 24-year-old, given that he only signed five months ago.

The midfielder averages more passes per game at 70 than any of his team-mates, whilst only Cristiano Ronaldo has made more key passes per match, via Whoscored.com.

Kroos is also only outdone by the Portuguese forward when it comes to making assists within the squad, and in the defensive third, he makes more tackles than any other Real Madrid player.

In La Liga, he has the highest pass completion rate, with Xavi and Andres Iniesta in second and third respectively, per Whoscored.com.

Only Rayo Vallecano's Roberto Trashorras and four Barcelona players make more passes in the whole of the division.

"Kroos is another professor," Ancelotti told Radio show Al Primer Toque, per ESPN.

He has graduated from Xabi Alonso's university very quickly. He surprises me because he is never worried. If he is under pressure or not, his play is always the same. I do not know his best position. He can always improve in the position he is playing, but at this moment it is not easy to see how. He plays the ball quickly, always the right pass, he does not give the ball away, he wins it back.

Those comments came after Kroos' most impressive game to date, in a 5-1 win over Rayo Vallecano, as the German scored his first goal for the European champions.

His importance to this team is underlined further when you consider he has played 1312 minutes in the league and in Europe, which is more than anyone else at Real Madrid.

With injuries to Modric and James at present, Kroos' adaptability maintains the balance of the midfield area.

Asier Illarramendi's introduction means that the team now has a habitual pivot, which allows Kroos more freedom to attack and move into advanced positions.

Kroos couldn't ask for a better start to life in Spain unless he was particularly harsh over his own scoring rate.