Daniel Arzani is expected to escape sanction from club side Melbourne Victory after a photo was circulated which showed the Australian international playing for an amateur team in Sydney.
Arzani turned out for Coogee United, his junior club, in a sixth division game last Saturday.
Victory declined to comment but informed AAP, Arzani's behaviour would be addressed when players begin to return to pre-season training later this week.
The Eastern Suburbs Football Association (ESFA) also declined to comment but said they were conducting an investigation into claims Arzani had played for Coogee United as a ring-in.
ESFA's rules dictate that players must be amateur and must be officially registered with the league.
Arzani is not expected to be fined for his actions, although new Victory boss Patrick Kisnorbo is likely to have taken a dim view of his behaviour.
It is also a bad look for Arzani, 25, to be playing for an amateur team on a rain-soaked pitch and risking injury.
The seven-cap Socceroo has endured a torrid run with injury over the early part of his career.
He has only recently worked his way back into the national team set-up under Graham Arnold, called up for June's World Cup qualifiers against Bangladesh and Palestine.
It was the first time Arzani had won a cap in close to six years and came after a sterling season for Victory in the A-League Men.
Upon his recall to the Socceroos, Arzani credited since-departed Victory boss Tony Popovic for helping him rediscover the form which once made him one of the most-coveted Australian youngsters.
"The biggest takeaway for me working under the boss (Popovic) this season has been the mental side of the game," Arzani said in May.
"It really helped with the team and the environment that I was in this year.
"We were very competitive, very professional, and it was a really great bunch of lads.
"They all got around me, they helped me out a lot, and I'm in a really good place right now.
"I've improved so much different aspects of my game that I didn't have before."
