Konstantinos Karetsas has already made a strong impression at Borussia Dortmund since joining from Genk for €30 million in the summer.
According to Sport Bild, Dortmund have high hopes for the 18-year-old, believing he could eventually reach a market value of €100 million and generate a significant transfer fee for the club.
To help Karetsas fulfil his potential and adapt to Niko Kovac’s style of play, former Liverpool analyst Roderick van der Ham has been assigned to work closely with him, the report adds.
According to Sport Bild, one of Kovac's demands is for the teenager to make more runs in behind opposition defences.
So far, Dortmund have only received nine-figure transfer fees for two players: Ousmane Dembélé, who joined Barcelona for €148 million, and Jude Bellingham, who moved to Real Madrid for €127 million.