Harry Kewell's agent has revealed that the Galatasaray winger has unfinished business in regards to the World Cup.

Kewell was a key player for the Socceroos in the 2006 World Cup in Germany, noted by his goal against Croatia and the fact he was injured for the Italy match in which the Aussies lost 1-0 via a late penalty.

Bernie Mandic has said that Kewell is determined to help his country qualify for the next 2010 World Cup and possibly get some revenge.

"The last World Cup was a massive thing in Harry's career, probably the highlight," Mandic told The World Game.

"To have such a high against Croatia and such a low few days later (against Italy) is certainly something that motivates a player to come back and do it bigger and better.

"The World Cup was unfinished business for him. Hence his burning desire to play in another World Cup."

Kewell is expected to return to Turkish League action in the coming weeks after having a hernia operation prior to Christmas.