Lee Wallace and Chris Iwelumo are major doubts for Scotland's Euro 2012 qualifier against Lithuania in Kaunas on Friday night.
The Heart of Midlothian defender Wallace pulled up with an ankle injury in the warm-up before the Premier League game against Dundee United at Tynecastle yesterday and had to be replaced.
The Burnley striker Iwelumo tweaked a hamstring near the end of his club's defeat against Swansea City on Saturday.
His manager Brian Laws said on Burnley's official website: "We will have to assess what Chris is like, but I would say it is highly unlikely now he will go with Scotland during the international break."
The Rangers manager, Walter Smith, said on Friday that Andy Webster was out of the squad. The Ibrox defender has sciatica but, like Wallace and Iwelumo, he will be assessed by the Scotland medical team when they meet up today at their Mar Hall hotel base, near Glasgow.
The Scotland manager, Craig Levein, has already lost his No 1 goalkeeper Craig Gordon to a broken arm and defender Gary Caldwell, who had two hip operations during the summer.