The 18-year-old will not travel with the squad for Tuesday’s Champions League game against Sabah FK in Azerbaijan and will also miss Saturday’s Bundesliga meeting with Eintracht Frankfurt. Dortmund managing director for sport Lars Ricken confirmed the news on Monday.
“Kos has a ligament injury in his foot. He will not travel to Baku and will not be able to play against Frankfurt on Saturday either,” Ricken said. “That is frustrating, of course, but we initially feared worse after seeing his teammates’ reactions.”
Karetsas was injured shortly after coming on as a second-half substitute in Saturday’s goalless draw away to Union Berlin. He replaced Maximilian Beier in the 62nd minute but was forced off around eight minutes later after twisting his ankle during a challenge involving Union captain Rani Khedira.
The Greek international was visibly in discomfort as staff helped him from the pitch. The initial reaction from his teammates raised concerns that he could face a lengthy spell out, making Monday’s update a measure of relief for Dortmund.
The club have not provided a firm return date. Ricken said the medical staff would assess Karetsas day by day after the Frankfurt fixture, meaning his availability for the following matches remains uncertain.
The injury comes at a difficult time for the teenager, who joined Dortmund from Genk during the summer and has been working to establish himself in the first team. He had made five Bundesliga appearances before the Union match, registering an assist.
Karetsas has already endured a worrying episode this season. He collapsed during Dortmund’s Champions League match against Villarreal in September because of circulatory problems and was taken from the pitch on a stretcher. Subsequent tests found no abnormalities, and he was able to return to action.
His latest setback is unrelated to that earlier incident, with the current problem affecting his ankle and foot. Dortmund will hope the ligament injury heals quickly, but the club have indicated that his recovery will be monitored rather than tied to a specific deadline.
For now, Karetsas is certain to miss the trip to Azerbaijan and the home match against Frankfurt. Dortmund will then reassess his condition before deciding when he can resume training and return to contention.