Celtic and Hibernian are likely to be without key players for vital Scottish Premiership derbies next week after they were named in Australia’s squad.
Martin Boyle, Jamie Maclaren and Mark Milligan, plus Celtic’s Tom Rogic, have been selected by head coach Graham Arnold for next month’s Asia Cup.
They will be available for their clubs’ fixtures on 26 December.
But an Australian Football Federation spokesman told BBC Scotland they cannot play on 29 December.
“This is two days over the Fifa regulation and has been communicated with all clubs,” he said.
“It ensures some players get an extra game in for their clubs and enjoy Christmas with their families and friends at home.”
They will then be expected to travel to Dubai to join the Australia squad heading for the United Arab Emirates, with the Socceroos beginning their campaign against Jordan at the Hazza Bin Zayed Stadium in Al Ain on 6 January.
Celtic, who returned to the top of the table by beating Motherwell on Wednesday, travel to Ibrox to face second-top neighbours Rangers on 29 December, while eighth-placed Hibernian host Hearts in the Edinburgh derby.
As Hibs have three players involved in the Australia squad, they are entitled to ask the Scottish Professional Football League for the postponement of their match against Hearts.
However, it is understood that, on this occasion, they have decided against this.
The Premiership enters its winter break following the derby fixtures until 23 January, but the clubs have Scottish Cup fourth-round tie four days earlier and also have league games scheduled before the Asia Cup final on 1 February.
After their opening fixture, Australia face further group matches against Palestine on 11 January and Syria on the 16 January.
Hibs host Elgin City in the Scottish Cup before league games against Motherwell, St Mirren then, a day after the Asia Cup final, Aberdeen.
Holders Celtic start their Scottish Cup campaign against Airdrieonians then face league games against St Mirren, Hamilton Academical and St Johnstone before again meeting the latter again in Perth on 3 February.