Sydney FC midfielder Brandon O'Neill has agreed to a deal to play for South Korea's Pohang Steelers, with the A-League leaders to receive an undisclosed transfer fee.
The highly regarded defensive midfielder won one Socceroos cap last June against South Korea.
The 25-year-old has been a mainstay of the Sky Blues side for the past four-and-a-half seasons, playing in two grand final-winning sides and a FFA Cup final victory.
The WA-raised player, who spent four seasons with Perth before joining Sydney, had made no secret of his desire to play eventually outside Australia.
"Now is the right time for me to accept a new challenge and to move out of my comfort zone again and to see what else I can accomplish," O'Neill said.
"I cannot thank the club enough for what they have helped me achieve.
"I have won two Championships, two Premierships, the FFA Cup and been named the club's player of the year and, for that, I will be forever grateful."
Sydney coach Steve Corica praised O'Neill's contribution to the club.
"Brandon has been immensely important to this club's success over the last five years and I would like to thank him on behalf of everyone," Corica said.
"He is an excellent player and we will be sorry to see him go, but I understand he feels he has achieved everything he can here at Sydney FC, and is keen to test himself elsewhere.
"More than that, he is an excellent person who more than deserves this chance and we've agreed we won't stand in his way."
O'Neill has played 145 times for the Sky Blues across domestic and Champion League competitions, scoring 10 goals for the club.