Nemanja Vidic is doubtful for Serbia's World Cup qualifier against Faroe Islands on Wednesday.
The Manchester United defender suffered an ankle injury in Saturday's game against Austria and had to be replaced at half-time.
It is not thought to be a serious problem but coach Radomir Antic admits he is 'not very optimistic' about the centre-back's
availability for the midweek trip to Torshavn.
Nenad Milijas' penalty earned Serbia a 1-0 victory over Austria and extended their lead at the top of Group 7 to five points.
France, Lithuania, and Romania are also battling to make it through to next season's tournament in South Africa.
But Serbia are firmly in control and victory over Faroe Islands would put them on the brink of qualification.