SCOTLAND have been dealt an injury blow ahead of their upcoming games at the end of this month.
Steve Clarke's side take on Ukraine twice and Ireland once in the latest round of UEFA Nations League games.
Ukraine will be back at Hampden on September 21, with the return fixture taking place in Poland on September 27.
In-between, Ireland will be in town on September 24.
The squad has yet to be announced for the crucial international games.
But it has been revealed that Stewart will not be part of it.
The ex-Ross County star picked up a thigh injury while warming up for Sunderland ahead of their clash against Middlesbrough earlier in the week.
It's undoubtedly a blow for both his club and country, with Stewart scoring five in seven appearances so far this campaign.
It is expected he will be out for up to eight-weeks while he recovers.
Tony Mowbray told the club’s official website: “Ross will be out for six to eight weeks.
"It could be a little longer, but that will depend on his rehabilitation and the way his body reacts.
“He’s a really positive guy and we hope that he will be a quick healer.
"We will take it game by game and hopefully he returns quickly.”