UPDATED: SYDNEY FC are poised to lose Socceroo midfielder Terry Antonis, after Greek club PAOK launched a $500,000 bid to lure the 21-year-old to Europe.

Two years after injury destroyed his dream switch to Italy, Antonis has flown back from Sydney’s pre-season camp on the Gold Coast in anticipation of a potential medical.

Talks between the clubs over the terms of the transfer are believed to be advanced, with the player unlikely to have trouble in agreeing personal terms.

Though sources cautioned that the transfer was not a “done deal” yet, Antonis and his advisers have long sought a move to Europe after twice having his hopes dashed.

Antonis actually signed for Serie A side Parma in 2013, but the deal was never ratified after he ruptured a thigh muscle ahead of the U20 World Cup in June that year - an injury that kept him out until February the following year.

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He was also due to join Everton as a teenager but was thwarted by FIFA’s change of rules on the transfer of players under 18.

PAOK were bought in 2012 by Russian billionaire Ivan Savvidis, who has paid off the club’s debts and invested heavily in players and staff.

Former Chelsea technical director Frank Arnesen was appointed to a similar role at PAOK, while Croatian Igor Tudor was hired in June as head coach.

media_camera Sydney FC’s Terry Antonis (right) gets a tackle in on Tottenham’s Andros Townsend.

Though Antonis’s departure will be a blow for Graham Arnold, who had planned to make the midfielder a starting member of his side next season, the return of Milos Dimitrijevic and the signing of Milos Ninkovic at least give him other options in the team’s engine room.

For Antonis the move will represent reward for his storming return from a fresh injury last season, a knee complaint that Sydney argued came from his time with the Socceroos at the Asian Cup. Antonis missed the second half of the regular season, returning only for the finals, but has worked intensely since on strengthening his physique.

If the move is completed he will also face a quandary at his new club later in the year, with Antonis likely to be a key figure in the Olyroos’ plans to secure a place at next year’s Olympics. Olyroo coach Aurelio Vidmar has organised a series of friendlies on FIFA dates later this year, ahead of a month-long qualifying tournament in January.

Meanwhile Melbourne City midfielder Aaron Mooy has signed a hugely improved deal to stay at the club, declining offers from overseas to stay in the A-League. City’s players were told on Monday that Mooy would reject advances reported to be from the Middle East and Europe, with City’s backers determined to keep a player who has blossomed since moving from the Wanderers.

It’s believed the multi-million-dollar package will keep Mooy at City for at least the next three years.