In a statement on their official website the Blues announced the completion of the deal and provided some comments from their newest recruit:
"I am really happy and excited to be here at Chelsea. It is an amazing feeling. I will try to do my best for this club. It is a new league for me, the beginning is always tough but I am sure the coach and my new team-mates will help me and I am looking forward to a great season."
In the three seasons since, he has been afforded only 37 La Liga starts and has not played a single minute in Real's three consecutive UEFA Champions League final victories.
That is not hugely surprising given his competitors for a starting spot at the Santiago Bernabeu have been Toni Kroos and Luka Modric, arguably the best midfield duo on the planet.
But Kovacic is a young player with enormous talent, and he would be a regular starter at a number of other top clubs.
The Croatia international is able to run at opposition defences, protect the ball well in possession and distribute with accuracy from the middle of the park.
Undoubtedly, Chelsea feel he can do a job for them in the engine room, and he will likely be allowed to flourish at Stamford Bridge as he wasn't at the Bernabeu.
Under manager Maurizio Sarri, a staunch advocate of the 4-3-3 formation, Kovacic could well make up a midfield trio with N'Golo Kante and fellow new signing Jorginho, per beIN Sports USA's Matteo Bonetti:
A season-long loan deal should work in favour of all parties as Kovacic will get the game time he desires and could then return to Real to succeed Modric, who will nearing 34 by next summer.