Hannover 96 have announced the captain Steve Cherundolo requires a second bout of surgery on his troublesome knee.
The 34-year old American defender had a minor arthroscopy in June but will now have a further operation which will force him to the sidelines for an unspecified time.
Hannover sporting director Dirk Dufner suggested the club would have to find a replacement for Cherundolo before the close of the transfer window.
"We must improve the right flank, or we'll encounter problems with the competitive nature of the Bundesliga," he told Bild.
