Scotland may have to go without striker talisman Lyndon Dykes against Denmark.
Steve Clarke revealed the in-form forward, who has scored in each of his last four international appearances, has a knock and is struggling to be fit for their final World Cup qualifying group game.
He sat out the 2-0 win against Moldova on Friday that secured the Tartan Army a playoff spot due to suspension.
Should Dykes not be fit to take on the Danes that could pave the way for shock call up Jacob Brown to make his first start.
The Stoke City striker came off the bench against Moldova and with Che Adams just one booking away from being suspended for the playoff semi-finals in March next year, the 23-year-old could find himself thrust into the limelight at Hampden.
A positive result, either a draw or a win, should be enough to see Scotland seeded for the semi-finals which would guarantee a home tie and, on paper, should see them up against a less difficult opponent.
Clarke will also have to do without Scott McTominay against Denmark as the Manchester United star hasn't recovered from a throat infection in time to feature.
Clarke said: "Scott is definitely out. Scott hasn't recovered enough from his virus.
"Lyndon didn't do very much this morning. Lyndon, I would put at 50-50."
Another squad player hoping to make their Scotland debut on Monday night is Celtic full-back Anthony Ralston.
He has found himself called into the fold after Nathan Patterson was ruled out through suspension.
Clarke added: "We lost Nathan to a second yellow, so we need cover in the right back position.
"Anthony has had a terrific start to the season with Celtic and fully deserves his call-up.
"Anybody I pick for the squad is a potential starter. I think I've shown I can call people into the squad and start them in games and Anthony's no different to anybody else."
