It’s understood the 25-year-old former Sydney FC defender will head straight to Adelaide to seek medical assistance from Harry Kewell’s one-time physio Les Gelis – one of the most respected names in the field.

It’s believed that the injury is bad enough to rule the former Olyroo captain out of selection contention for new Socceroo coach Holger Osieck’s first Australian squads for friendlies against Poland and Switzerland early next month.

Milligan injured his groin in the lead up to his J2 club Jef United Chiba’s game against FC Gifu on Sunday. United lost 1-0.

The former Chinese Super League player also missed the Socceroos' recent friendly with Slovenia due to injury.