Sunderland full-back George McCartney may miss the first month of the season, according to his Northern Ireland boss Nigel Worthington.
The defender suffered an ankle injury in the Black Cats' pre-season game against Brighton last week and has been receiving treatment since in a bid to be fit for the start of the campaign in less than a months time.
However, Worthington has revealed the Sunderland star is "touch and go" for Northern Ireland's opening European qualifier in Slovenia on September 3 as he is facing around six weeks on the sidelines.
"George is definitely out of the Montenegro friendly on August 11. That is too soon for him," Worthington said.
"He is out for four to six weeks so even Slovenia is very doubtful at this moment in time.
"We are waiting to see the results from a scan he had on the ankle, and it is touch and go with regards Slovenia.
"He has had hard luck with injuries in recent months, but it is part and parcel of the game."