Cologne goalkeeper Timo Horn is likely to be sidelined for the rest of 2016 after undergoing surgery on an injured knee.
Horn, who has been a mainstay of the club's rise to sixth in the Bundesliga, conceding just seven goals in nine appearances, injured his right knee in training on Wednesday.
The 23-year-old will undergo surgery on Thursday and is expected to be out until at least the turn of the year, although Cologne gave no indication of when he was due to return.
A statement on their official website said: "FC Koln team doctor Peter Schaferhoff diagnosed Timo Horn with a knee injury, which will require immediate surgery.
"The surgery will take place on Thursday. It remains to be seen how long Timo Horn will be on the sidelines. FC Koln wishes Timo Horn a speedy recovery."
Only Bayern Munich's Manuel Neuer has conceded fewer goals than Horn this season, with the Germany number one beaten six times.