Kilmarnock striker Eamonn Brophy has been called into the Scotland squad after Lawrence Shankland pulled out with a minor injury.
Shankland did not feature in Saturday's 2-1 win in Cyprus with Steven Naismith starting up front and Oli McBurnie coming on just after the hour mark.
A Dundee United statement read: "Lawrence Shankland has left the Scotland squad due to a slight injury picked up ahead of Saturday's match v Cyprus.
"He will return to the HPC (High Performance Centre) for assessment and is expected to be available for the Morton game."
Brophy, who has four caps and has scored three times for Killie this season, will come into the reckoning for Tuesday's final Euro 2020 qualifier against Kazakhstan at Hampden.
A draw would seal a third-placed finish for Scotland but they are looking for a third victory in succession to build confidence ahead of their play-off campaign in March.
