Karetsas's injury comes just days after his compatriot Giannis Konstantelias suffered a ruptured cruciate ligament in his knee during a Bundesliga match against Hamburg. The two players were signed by Borussia Dortmund this summer for a combined total of 56 million euros, with Konstantelias arriving from PAOK Salonique for 26 million euros and Karetsas from Genk for 30 million euros.

The 18-year-old Karetsas was hospitalized for further examination after the match, with Borussia Dortmund stating that he had suffered from "circulatory problems". The exact nature of the injury is still unclear, but it is a significant setback for the young player and his club.