Liam Bridcutt is out of the Scotland squad to play England at Wembley on Wednesday night, assistant manager Mark McGhee has confirmed.
McGhee was reluctant to reveal the nature of the injury but it is understood the Brighton midfielder is suffering from a groin problem which is why he did not join up with the squad at their hotel in St Albans.
McGhee is hoping Scotland build on their 1-0 World Cup qualifying win over Croatia in June, albeit there is no chance of reaching the finals in Brazil next summer.
He said: "We have all fed off the result and the performance but also the reaction at home to it has brought everyone fresh hope that things from this point could improve.
"Everyone has benefited from that.
"Going around Glasgow or talking to people, suddenly it is positive again which was very much needed.
"That generates confidence throughout the camp."