Feyenoord defender Serginho Greene is facing up to a long spell on the sidelines with a knee injury.
The defender was carried off five minutes from time as Feyenoord drew with AZ Alkmaar at the weekend.
Greene will be sent for a scan, but club doctor Robbart van Linschoten fears he may have suffered cruciate ligament damage.
If that proves to be the case, he is almost certain to miss the remainder of the season and could even struggle to be available for the start of the next campaign.
Angelos Charisteas also picked up an injury against AZ, but the Greek forward is expected to be sidelined for weeks rather than months with his hamstring problem.