Scotland captain Darren Fletcher is likely to miss crucial matches against the Czech Republic and Lithuania.
The Manchester United midfielder has been excluded for next week's friendly against Denmark as he builds up his fitness following a mystery virus.
Scotland coach Craig Levein said: "I hope to have him available for the October matches.
"If things go exceptionally well, then I'll have a look at the situation again for September."
Scotland host the Czechs on 3 September before Lithuania visit three days later and Levein's men realistically need to win both matches to keep their Euro 2012 play-off hopes alive before facing Liechtenstein and Spain away the following month.
Fletcher missed two months of last season's run-in for Manchester United, although he played 90 minutes against Blackpool on the final day of the Premier League campaign.
The 27-year-old was left out of United's tour party for their pre-season trip to the United States in order to work on his fitness.
Fletcher last week declared himself "fighting fit", but Levein feels the player needs games before throwing him into the Euro 2012 qualifiers at Hampden.
"It's extremely difficult for me if he's not playing for his club to include him in the squad," added Levein.
"I have spoken to Darren twice in the last two weeks just to make sure he's progressing.
"I'm in constant contact with him. I went down to meet him at the end of last season and had a long chat with him.
"I desperately want him back in the squad, more than anybody, but he has to have played some football.
"I can't just put him back in the squad because he's a good lad.
"I think it's important he is back on the field for Manchester United and back playing 90 minutes, and also gets his confidence back, because he has been out for a long time."