Scotland are confident Kenny Miller will be fit for next week's Euro 2012 qualifier against Spain, but the striker remains a big doubt for Saturday's game with Liechtenstein.
Cardiff City forward Miller picked up a groin injury during his side's Championship defeat at Hull City on Saturday and is a concern for national team coach Craig Levein.
He is expected to fly out with the rest of the squad on Thursday for the game in Liechtenstein, but he is unlikely to be risked against the group minnows.
Brighton & Hove Albion hot shot Craig Mackail-Smith looks likely to come in against Liechtenstein, but assistant boss Peter Houston hopes Miller will be ready for the crunch game away to Spain.
Houston said: "Kenny Miller is still with us, he's progressing by the day.
"Kenny came up on Saturday evening and stayed here and the difference between Saturday and Sunday and him feeling better was quite amazing.
"It is going to be difficult perhaps for Saturday but certainly Kenny is more than hopeful and is still progressing. No-one knows their own body better than himself.
"He is working away with the physios and hasn't joined our sessions yet. Saturday might be difficult but certainly for Tuesday I have high hopes for him."
Scotland only have three listed strikers in their squad, with David Goodwillie the back-up for Miller and Mackail-Smith, but the Bluebirds striker's fitness doubt has not prompted another call-up.
"We haven't really spoken about bringing anyone else in with regards to that," Houston said.
"I think it will be as you are with regards to the striker department if Kenny doesn't make it.
"Craig Mackail-Smith is a bit similar to Kenny - he works very hard, is very, very quick and, more importantly he is scoring goals and in very, very good form."
Houston confirmed Kilmarnock goalkeeper Cammy Bell had replaced Matt Gilks in the squad, while Lee Wallace came in for Stephen Crainey on Sunday.
Aston Villa right-back Alan Hutton has been receiving treatment for a knee injury while Leeds winger Robert Snodgrass has an ankle problem but both are expected to be fit.