The Socceroos missed out on direct qualifcation to Russia on goal difference, with Japan and Saudi Arabia taking the spots.

Mooy will head to Malaysia and then back home to Sydney in the next week and a half to face the Syrians in the two-legged World Cup playoff.

If the Socceroos are successful, the Huddersfield midfielder will then be called on to face the fourth placed CONCACAF side for two games in November.

Asked about Mooy's national team involvement, Wagner was pragmatic and honest.

"What I wished was that they would already be qualified and that he should not maybe go and play Syria in the playoff semi-final," he told the media.

"And then maybe the next opponent in the next international break in the final. This is what I wish. After this season, if he is then able to play in the World Cup, if he gets qualified for the World Cup and gets a chance to play in it then I will be very happy for him.

"And I will be much more happy if we have a positive result with the club and he goes to Russia after this season. This is something I have to accept and deal with it. It's nothing I can wish and it happens, that makes no sense for me to think about what I wish."

The Terriers will be forced to release Mooy for the qualifiers under FIFA guidelines.

The Socceroo has been a key figure in Huddersfield's first season in the English Premier League after snaring promotion.