Fink knows the Black and Yellows' new signing from their time together at Belgian top-flight club KRC Genk. The former Germany international coached there from June 2024 to December 2025, while Karetsas came through the club's academy.
"He is a little magician, a very creative midfielder with superb dribbling. In a possession-based team like Dortmund, he will be able to achieve a great deal with that, it fits well. He can be really exciting there if he gets his freedom," was Fink's verdict on BVB's new signing.
Still, the Greek is only 18 and nowhere near the end of his development. "He can and must get better, still learn a great deal," Fink analysed his former protégé and added: "For example with regard to his risk management. When do I have to play or hold the ball? When should I take the counter and go into the dribble?"
There, Karetsas still needs "more experience. At 18, he simply cannot have that yet. It will come automatically with match practice," said Fink. The 18-year-old simply has to "be patient. He must not think that he can already do and know everything."
Expectations in Dortmund will be very different from those at Genk. On that front, Fink warned against too much pressure weighing on the attacking player. "Expectations are high given the fee. I hope that does not become a problem. Especially if things perhaps do not go so well for him or the club at some point."
Getty ImagesKonstantinos Karetsas scores in Dortmund friendly against Arsenal
BVB officially completed the transfer of the 10-cap Greece international just under two weeks ago. In Dortmund, Karetsas signed a contract until 2031, while around €32 million went to Belgium in return.
That makes the 18-year-old slightly cheaper than Dortmund's previous record transfer Ousmane Dembele, who joined the Westphalians from Stade Rennes in the summer of 2016 for €35 million.
The Greek made an instant impression on his debut. He scored straight away in last week's 3-2 friendly win against Arsenal.
Following the arrivals of Joane Gadou, Kaua Prates and Justin Lerma for a combined total of around €30 million, Karetsas is already BVB's fourth new signing this summer. Borussia's transfer business is not finished yet, however. Karetsas' compatriot Giannis Konstantelias and Joey Veerman of PSV Eindhoven are also on the verge of moving to the Black and Yellows.