Scotland manager Walter Smith has suffered two call-offs for the 'B' international against the Republic of Ireland.
Hibernian skipper Kevin Thomson has the flu while Celtic forward Shaun Maloney has a calf injury.
Maloney, 23, came off midway through the second half of the Bank of Scotland Premier League leader's 3-1 victory at St Mirren on Sunday.
Thomson, who is also 23, was withdrawn an hour into his side's 2-0 triumph over Inverness Caledonian Thistle on Saturday after falling ill the day before.
But Smith has not drafted in any replacements to his original 18-man squad for tomorrow's game at Dalymount Park in Dublin.
He said: "We have decided not to call in anyone else at this late stage. We are just going with the 16 players."
But the Scotland boss believes the game is a chance for former Under-21 players to stake a place in his full squad.
Smith said: "There are a lot of guys who are out of the Under-21 side now and in limbo in terms of international football.
"That is the main objective — to make sure the players who are to old for the Under-21s have an opportunity to get international games."
Wigan defender Andy Webster will skipper the Scots as he continues his comeback from a lengthy absence.
The 24-year-old was frozen out at Hearts last season after negotiations over a new contract stalled and a calf injury delayed his debut for the Latics.
However, Webster has been involved in every game of Wigan's current four-match winning streak, and Smith wants to give him extra match-practice in Dublin.
The Scotland manager said: "We're glad he is back after about six months out of football.
"He looks as though he is on his way back, but he still feels he is a little short of match fitness. This game will help him and it's good for both parties.