AZ Alkmaar have revealed that keeper Joe Didulica will not play again this year.
The Croatian was concussed during the clash with PSV Eindhoven in October and has not featured since.
AZ coach Louis van Gaal says Didulica is still suffering from headaches and insists there is no timescale for his return.
"It's not going well," said van Gaal. "He is still bothered a lot by headaches.
"He won't return before the winter break.
"We have to be very careful with his injury. Certainly while he still has got headaches, we have to wait."