Born in Linz, just one hour away, a return to the city where Mozart was born takes the Chelsea midfielder back to the country where it started for him.
Kovacic has fond memories of his childhood in Austria. His Bosnian-Croat parents, Stipo and Ruzica, had moved there to work and he lived there until he left to move “home” to Croatia to join Dinamo Zagreb, aged 16.
On Tuesday, Kovacic is back in the country of his birth to help Chelsea secure qualification to the knockout stage of the Champions League.
The 28-year-old is becoming one of the most important players at Stamford Bridge.
No more so was that evident than against Manchester United on Saturday, when his introduction off the bench in the 36th minute changed the game.
Chelsea were being over-run and outplayed by United, but Kovacic gave them control in midfielder as head coach Graham Potter (right, at training) switched from a 3-4-3 to a 4-4-2 formation. Kovacic made headlines after the game when he stripped down to his pants after throwing his shirt and shorts into the crowd.
The way he is playing, Potter will hope to have him back in a Chelsea kit as regularly as possible this season.
The Blues boss revealed after the 1-1 draw with United that Kovacic has been struggling with a knee injury all season and needs to have his minutes managed.
And, with growing doubts over the futures of N’Golo Kante and Jorginho, Chelsea are increasingly aware of his worth.
He brings crucial balance to their midfield. He has the vision and range of passing to pick apart opponents from deep and also wins tackles and gives cover to the defence.
Chelsea are understood to be playing a delicate balancing act with his fitness after Kovacic missed a month out earlier in the season. They are not too worried about his knee issue getting worse, so long as he is not overused. With Kante out for four months, it is pivotal that they get that balance right.
There is also a desire to start talks over a new contract next year after the World Cup, with less than two years remaining on his deal.
Kovacic would be open to discussing a new contract, having grown comfortable in west London off the field, as much as on it, getting married to his long-time partner and having their first child.
Chelsea are top of Group E after impressive back-to-back wins over AC Milan and victory tonight will see them qualify for the knockout stage with a game to spare.
The Blues will also go through if they draw and Milan beat Zagreb in the other match in the group. They will be confirmed as group winners if they win and Dinamo do not.
Against a Salzburg side who drew 1-1 at Stamford Bridge in Potter’s first game in charge last month, Chelsea will be without defender Kalidou Koulibaly after he was ruled out with injury.
Potter is likely to stick with the 4-4-2 diamond that worked so well against United — and do not be surprised to see another influential performance from Kovacic, as Chelsea increasing rely on their Austrian-born Croatia star.