Defender Andrew Robertson has been ruled out of Scotland's Euro 2016 qualifier against Germany on Sunday.
The Hull City full-back, who is suffering from a calf strain, revealed on social media that he will miss the Group D opener in Dortmund.
Centre back Christophe Berra was also forced to withdraw from the squad earlier this week.
The Ipswich defender has been ruled out of the match against the World Cup winners with a knee injury.
Meanwhile, manager Gordon Strachan admits his side are in a battle for second spot as they prepare to kick off the campaign to reach their first major finals since the France 98 World Cup.
Strachan's side face World Cup winners Germany in Dortmund on Sunday in their opening match of qualifying Group D.
Republic of Ireland, Poland, Georgia and Gibraltar are also in the group.
"Germany will qualify. Poland, Scotland, Georgia and Ireland for the other two spots, that's a mini league," Strachan told BBC Scotland.
"Gibraltar are not going to qualify, I'd imagine they will be looking for one scalp from this campaign and that would make their campaign.
"We just need to make sure it's not our scalp they get."
The national manager is well aware the Scottish public are desperate to see their side reach a first major tournament since France 98, with the top two teams in the group qualifying automatically and the third-placed sides going into play-offs.
And, while Strachan says the fans will realise Group D is "a bit of a tough one", he would love to secure a berth at France 2016 to end the wait for an appearance at a major finals.
"We'll try to deliver that dream, that's for sure," he added. "Let's make it a great campaign and let's all enjoy it."
Strachan reckons the tournament would benefit hugely from Scotland being there.
"It is a festival of football, but it's also a festival of people getting together and celebrating the game," he added.
"The Scottish and Irish celebrate life better than anybody else, that's for sure.
"The problem is we are in the same group this time."