McDonald has been in fine form since joining Celtic, scoring for the club in Europe during the week against Spartak Moscow and setting up one and scoring the other at the weekend.

He is tipped to take over Mark Viduka’s striking duties upfront for the Socceroos when the veteran hitman retires from international duties.

And he looked likely to lead the Australian attack against the star-studded Argentinians in next week’s game in Melbourne, with Viduka staying in the UK for the match.

But overnight it was revealed he’s now in doubt to even make the journey Down Under, leaving Socceroo stand-in coach Graham Arnold with a selection nightmare in attack.

According Glasgow’s Evening Times, McDonald is nursing a hamstring injury following the weekend blitz on St Mirren. He played 70 minutes before being taken off when his club were 4-0 up.

Now he is set to be assessed by physios at Celtic before a decision is made on whether to allow him to travel to Australia.

McDonald has already chosen his club over country when he stayed with Celtic over the close season to train with his new team-mates instead of taking part in the Asian Cup with the Socceroos.

“Boss Gordon Strachan wants to make sure the injury is not exacerbated as it could rule him out for three weeks with the Champions League opener in Donetsk on September 18,” the Evening Times said overnight.

“McDonald is keen to turn out for his country, but knows the dangers of aggravating the hamstring injury.”

Celtic manager Strachan is delighted with McDonald’s current form which has cemented his first team place at the Scottish club. After the St Mirren match, he poured praise on the 24 year old.

“"For a period of about 20 minutes, Scott was simply unplayable,” said Strachan. "But to get that to level and to create that platform for yourself, you have to really put the work in. And Scott did that."

McDonald is set to talk to Graham Arnold after his medical before making any final decision on returning to Australia.

If he pulls out, Australia could find itself short on firepower with Josh Kennedy still reovering from a long-term injury and Brett Holman struggling to find the target in his last few games for the Socceroos.

However it could be an opportunity for A-League Socceroos Archie Thompson and Alex Brosque as well as former Newcastle Jet Nicky Carle to shine against the likes of Carlos Tevez and Lionel Messi.