Izzo has signed a contract with Super League Greece 2 side Xanthi FC, coached by former Western Sydney and Perth tactician Tony Popovic, with United receiving an undisclosed transfer fee.

The 25-year-old Izzo's transfer comes after sterling domestic seasons and also three FFA Cup wins.

""It is always hard to see the best talent leave the club and in our opinion Paul is the most talented goalkeeper in Australia," United's football director Bruce Djite said in a statement on Thursday.

"Paul has had over three successful years here as our number one goalkeeper and has been an instrumental member of the team.

"However as a club we believe in fostering talent and subsequently supporting those who wish to pursue careers abroad."

Australian Associated Press