Sammy Clingan has been ruled out of Northern Ireland's World Cup qualifier against San Marino on Wednesday.
The Norwich midfielder has suffered a thigh strain and will be forced to sit out the crunch clash.
Clingan broke down during training and is now set to return to Carrow Road for treatment.
Manager Nigel Worthington said: "It is a disappointment as Sammy is a big player for us.
"He did not train Sunday and yesterday and had to step out of today's session, so he will be going back."
Meanwhile, Clingan's fellow midfielder Dean Shiels is a doubt after picking up an ankle injury and striker Warren Feeney is struggling with a virus.
However, experienced defender George McCartney has recovered from a case of severe blisters and looks set to feature.