The potential scenario comes on the back of the postponement of the World Cup semi-final play-off tie against Ukraine which was originally scheduled for next week.
Scotland will instead play a friendly against Poland with £10 from each ticket sold supporting UNICEF’s humanitarian response to the ongoing crisis in Ukraine following the Russian invasion.
But Clarke must try to focus on football amid these bigger issues and he is concerned for players’ welfare if Scotland – or indeed Ukraine – are ordered to fulfil such an unprecedented schedule of fixtures.
The Scotland manager's main wish is that the Ukraine situation is resolved to the extent that the play-off semi-final can go ahead in June.
“We hope and pray that we are playing Ukraine in the semi-final play-off,” he said. “What happens with the rest of the month, I don’t know is the honest answer. All the big wigs are still in discussions and trying to find a solution.”
Fifa confirmed last week that the Scots’ play-off clash against Ukraine has been re-arranged for a date in June to be confirmed. It had been assumed this would mean rearranging one or more of the Nations League clashes already scheduled for ten days between 4 and 14 June. Some surprise had already been registered at this intense schedule after such a long season.
But Clarke reported that the governing bodies are planning to stage the play-offs in addition to the existing games. One possibility is extending the window beyond 14 June, which would mean players having an even shorter break.
Scotland are already due to play Ukraine in a Nations League encounter as well as Armenia (twice) and Republic of Ireland.
“I’m desperate not to be in a position where we might have to play six games in June because I think that would be too much for the players on the back of a long hard season,” said Clarke.
“At the moment that seems to be the thinking – that we might need to squeeze six games into a June window which is not correct in terms of player welfare.
“Just the timing of it, on the back of a long hard season … even a four-game window was going to be a little bit unusual in the Nations League. To try and squeeze in a play-off semi-final and hopefully a final would take it to six games, which is too much.
“I think those are the discussions they are having at this moment in time,” he added. “You’ve got to put it all into context in terms of what Ukraine are suffering at this moment.
“These are mere sporting matters. Ukraine could also be in a position where they might have to play six matches and unfortunately we’d be knocked out.
"I think for everyone, the people who organise the fixtures and the international calendar, I think they’ve shown before that in certain circumstances, they can move the fixtures around.
“Maybe this is a case where they are going to have to help us out and move some fixtures away from June.”