Borussia Dortmund must apparently prepare for the possibility that summer signing Konstantinos Karetsas will not be available for upcoming fixtures.

According to Ruhr Nachrichten, the BVB star faces weeks-long absence. Karetsas suffered a right ankle injury on Saturday afternoon during the Bundesliga away match at Union Berlin (0:0), just minutes after being substituted on. An exact diagnosis is still pending.

According to the typically well-informed newspaper, Karetsas was traveling on crutches upon his return to Dortmund.

BVB manager Niko Kovac explained after Saturday's goalless draw in the capital that the ankle joint had been affected and that they would examine the injury, noting that it was certainly unfortunate that Karetsas suffered an ankle injury after such a short time. Sporting director Ole Book added that Karetsas was not feeling well at the moment. Chief executive Lars Ricken declined to provide a specific diagnosis and referred to the results of further examinations.

BVB colleague Konstantelias sidelined long-term

Karetsas joined Borussia Dortmund in the summer from KRC Genk in Belgium. The 18-year-old forward has already dealt with circulation problems this season. His Greek compatriot Giannis Konstantelias suffered a torn anterior cruciate ligament just weeks after arriving at BVB in late August.

For Borussia Dortmund, fixtures come thick and fast: the Black and Yellows travel to Sabah FK in Baku for a Champions League match on Tuesday evening at 6:45 PM CET. The Bundesliga home fixture against Eintracht Frankfurt follows on Saturday at 6:30 PM CET. The following week on October 27 at 8:45 PM CET, BVB hosts Werder Bremen in the DFB-Pokal. Dortmund can ill afford to lose players to injury.