Zullo was due to fly out today for the game against the Singapore national team on Saturday but instead will have to be content with watching the match on television as he concentrates on regaining full fitness.

It’s a bitter blow for the 19-year-old who made such an impact last season but coach Frank Farina says disappointments such as this are all part of the steep learning curve that is professional football.

“It’s a blow for Michael and he is terribly disappointed but these things happen in football and all setbacks make ultimately make you stronger.

“He did enough to get himself noticed and he will get his chance again,” Farina said.

Club physio Tony Ganter doesn’t expect the injury to hamper Zullo’s pre-season training regime with the players due to report back in around a month’s time.

“Michael’s irritated the attachment of his right patella tendon and inflamed the growth plate on his shin," he said.

“We treated it during the week and it settled to a degree, but he was unable to train at full intensity on Friday last week.

"Following liaison with the Socceroos medical staff, the directive from Pim Verbeek was that all players who were coming to camp on Monday needed to be 100% fit and have absolutely no deficits in their function or limits in their training.

"Obviously Michael wasn’t able to fulfil those criteria so he was withdrawn."

He added: “The injury is not that bad, he’s just stirred it up.

"If he’d had an extra week he probably would have made it, so I think by the end of this week he’ll be right to get back into it.

"But in light of his program and the fact that the squad are resuming on April 14, he’ll probably now just do his rehabilitation."