Augsburg have confirmed defender Jeffrey Gouweleeuw has undergone a successful operation to repair a collapsed lung.
Gouweleeuw had complained of breathing problems and was examined by the team doctor and pulmonary specialists, the club said in a statement.
Augsburg expect the 25-year-old, who has played every minute of their season, to be unavailable until early 2017.
"The Dutchman suffered a spontaneous pneumothorax (collapse of the lung) and already went under the knife on Thursday," the club said. "According to the doctor, the operation was successful.
"The 25-year-old will almost certainly not be available for [head coach] Dirk Schuster, before the winter break. Gouweleeuw's exact time out on the sidelines depends on how the healing process runs."
Injury news: has suffered a collapsed lung and will be out for at least one month. Get well soon, Jeff! October 7, 2016
Sporting director Stefan Reuter admitted the loss of Gouweleeuw comes as a big blow to Augsburg, who are already without Jan-Ingwer Callsen-Bracker, Marvin Friedrich, Caiuby, Dominik Kohr and Raul Bobadilla.
"This is a bitter injury both for Jeffrey and the team, particularly as our list of long-term injuries has now increased," he said.
"However, Jeffrey's health counts the most. We are confident that he will be able to overcome this injury."
