The Scottish Football Association has set a Monday deadline to appoint the new Scotland manager - but the job will not be going to Aberdeen boss Derek McInnes.
It is understood Hampden chiefs have decided they cannot afford to wait any longer than early next week to decide on Alex McLeish's replacement.
The squad for next month's crucial Euro 2020 qualifiers with Cyprus and Belgium is due to be announced on Tuesday, May 28, and the SFA wants to give the new man in charge at least a week to draw up his first selection.
McInnes' decision means Kilmarnock boss Steve Clarke now appears to be out on his own as the leading contender to take over from McLeish, who was sacked last month.
By setting a deadline for Monday, the governing body appears to be giving Clarke the time he needs to complete this season's duties with Kilmarnock before making their move.
Killie host Rangers at Rugby Park on Sunday as they play their final Ladbrokes Premiership fixture of the campaign.
Former West Brom and Reading boss Clarke confirmed last month he had received no contact from Hampden chiefs about taking over as Scotland manager but did admit he would be interested in the position "at some stage".
He added: "Whether it is now or not is a matter for you guys to talk about and speculate.
"I am fully focused on finishing the season well here at Kilmarnock.
"I don't speculate, there is no point in doing that. I know how football works. I am fully focused on this job here."