Marco Reus faces a lengthy spell on the sidelines after suffering knee ligament damage in Borussia Dortmund's 2-1 DFB-Pokal final win over Eintracht Frankfurt at the weekend.
The Germany international was forced to stay behind in the dressing room at half-time after sustaining a knee problem, making way for Christian Pulisic.
He has since undergone further examination to determine the exact extent of the injury and BVB have now announced Reus has suffered a partial tear of the cruciate ligament in his right knee.
"Borussia Dortmund's Germany international Marco Reus will be out of action for several months after sustaining a partial tear of the cruciate ligament in his right knee in Saturday evening's DFB Cup final against Eintracht Frankfurt at Berlin's Olympiastadion," a statement on the club's official website reads.
"Further examinations will be conducted over the next few days to determine what course of treatment is required. With this in mind, Borussia Dortmund will not at this stage make any precise estimations as to the possible length of the player's absence.
"BVB wish their DFB Cup hero the speediest-possible recovery."
Reus has endured a difficult 2016-17 campaign in which injuries limited him to 24 appearances in all competitions, the winger scoring 13 times.