Former Bayern Munich midfielder Niko Kovac paved the way for U.S. international Christian Pulisic's transfer to Borussia Dortmund in 2014.
Pulisic was 15 at the time, living in his homeland of the United States, but according to FIFA statutes, he would not have been allowed to move to Germany as a non-EU player.
However, Pulisic's grandfather Mate has Croatian roots and contact with then-Croatia coach Kovac and his brother, former Bayern and Dortmund defender Robert, helped him secure his move to BVB.
"Niko Kovac supported me back then in getting my Croatian passport. He helped me a lot," Pulisic told Sport Bild.
"It was always my dream as a young boy to play for a top club in Europe. When the opportunity to play for BVB came up, I really wanted to take it."
Niko Kovac, currently in charge of Eintracht Frankfurt, said he was more than happy to help out Pulisic.
"Christian is a good lad," he said. "My brother and I helped him and we were in contact with Borussia too. We had the right contacts in this matter and of course we were very happy that everything worked out."
Niko Kovac had a good relationship with Dortmund at the time, using the 2013-14 winter break to sit in on club training with then-coach Jurgen Klopp, and had been touted as a potential successor to Thomas Tuchel before BVB appointed Peter Bosz this summer.
Dortmund play Frankfurt in the Bundesliga at the Waldstadion on Saturday.