Sunderland are waiting for the results of scans on Steven Fletcher's crocked ankle.
The striker was stretchered off early in Scotland's 2-1 World Cup qualifying loss to Wales on Friday and is expected to be sidelined for the remainder of the season but the club want to learn more about the extent of the problem before making an assessment.
"Sunderland's Steven Fletcher has returned to Wearside after picking up an injury with Scotland," read a statement on the club's official website.
"The striker landed awkwardly during the game with Wales at Hampden Park and was stretchered off after just two minutes.
"Fletcher is currently being assessed by the club's medical team and is awaiting scan results to find out the extent of his injury."
