McGree, Melbourne City's Lachlan Wales and Nathaniel Atkinson plus Perth Glory's Brandon Wilson were found to have committed "unprofessional conduct" over an incident involving a woman.

The quartet were in Cambodia with the Olyroos for the AFC U-23 championship qualifying tournament at the time, with the woman issuing a complaint in April, leading to a FFA investigation.

McGree - who was Olyroos captain at the time of the incident - has been banned from international duty until April 1 next year while Wales, Atkinson and Wilson were hit with longer bans through to August 10 - ruling them out of a potential Olympics campaign if the Olyroos qualify for Tokyo 2020.

All four players will miss January's AFC under-23 championships in Thailand, the qualifying tournament for Japan.

Adelaide United confirmed McGree would not be appealing his FFA sanction and the 21-year-old will be available for selection in the A-League both during and after his ban.

Adelaide United will not be imposing any further sanctions on McGree as he was at Melbourne City - on loan from Club Brugge - at the time of the incident.

Meanwhile, Wales and Atkinson will remain in contention at City, with the club to await the outcome of any potential appeals process before determining any internal sanctions.

Wales and Atkinson are currently exploring their options in regards to an appeal.

City midfielder Josh Brillante said City were rallying around the pair.

"Look, that's a situation that I don't really want to comment on but they seem to be OK and all the boys are getting around them and supporting them," he said.

"We're just doing the same stuff that we have been every week and preparing for the next game."

Perth Glory confirmed Wilson will be eligible for A-League selection going forward, with the international ban considered a matter for the FFA.

Australian Associated Press