Kovacic’s appearance at Chelsea, even though it was part of Real Madrid’s contract to buy Thibaut Courtois, is still easy to understand with this team’s existing system.

All the talk around Stamford Bridge in the summer of 2018 was mostly negative.

Kovacic came to Chelsea with the expectation of being a regular starter.

In addition to the record $92 million contract for goalkeeper Kepa Arrizabalaga to replace Courtois, Chelsea’s efforts to improve their strength are focused on the midfield, with the presence of Kovacic and Jorginho.

Jorginho will take on the role of commander of the midfield and carry out Sarri’s instructions on the field, just like he did in three seasons at Napoli.

With the ability to lead the play, Jorginho will likely be the one to keep pace in Chelsea’s midfield trio.

Jorginho - Kovacic - Kante: Lungs in the middle of Chelsea's field

Sarri’s football philosophy takes a lot of time for students to absorb.

The two wide midfielders in Sarri’s midfield defensive trio must both support the attacking players and put pressure on the opponent when they don’t have the ball.

While working at Napoli, Allan played Kante’s role in Sarri’s setup.

Kovacic is a mobile midfielder.

Jorginho - Kovacic - Kante: Lungs in the middle of Chelsea's field

Kante is considered a world-class midfielder for Chelsea.

The biggest question for Kovacic is just his absence in the most successful World Cup in the history of Croatian football?

Barkley has been outstanding in the early pre-season, and Sarri has almost guaranteed the English student a place in the squad.

No matter who Sarri chooses to play, his system still needs more time for new students to adapt.

Jorginho - Kovacic - Kante: Lungs in the middle of Chelsea's field

Jorginho will be the leader of Chelsea’s midfield.

In the defeat against Man City in the English Super Cup, Chelsea somewhat demonstrated `Sarri-ball` with coordinated passes in the middle.