Speaking for the first time since taking up his new post with J-League heavyweights Yokohama F Marinos, Postecoglou said he was excited to return to club football in a strong overseas league that could act as a stepping stone to Europe.

He also addressed last month's resignation, one that shocked his Socceroos squad and "puzzled" Football Federation Australia chief executive David Gallop.

While acknowledging the decision six months before the World Cup had let down the players, the 52-year-old also expressed disappointment towards some quarters at what he perceived was an undermining of the Australian game.

"I'd love to say, this is the reason," Postecoglou told Fox Sports News.

"Some of it is personal, some of it is professional. Some I don't see the point in bringing up right now.

"I think in the context of time I may be able to sort of talk about things further, but I've always been a huge advocate, or disappointed when people try and bring the game down in the country.

"We're probably world champions at that, to try and beat ourselves up as a game in this country. I've always tried to make sure I never do that.

"To bring up something that isn't actually the pivotal reason, but one of the reasons I'm leaving, if I don't think it's going to serve a purpose or help the game, I'm just not going to talk about it."

He again denied a falling out with FFA had contributed to the move.

Postecoglou said part of his reason for quitting centred around a feeling he'd achieved everything he'd set out to.

That included creating a new team and implementing his staunch attacking philosophy, one that helped the Socceroos win the 2015 Asian Cup and qualify for a fourth consecutive World Cup.

He will now set about applying that same style to Yokohama, who finished fifth in the season just finished.

After spending time shadowing Pep Guardiola at high-flying parent club Manchester City, Postecoglou will embark on his first pre-season with the Japanese club Socceroos defender Milos Degenek calls home.

And he did not rule out bringing in other Australian internationals ahead of Russia 2018.

"At the moment Yokohama has still got some pretty important games - a (Emperor) Cup semi-final and potentially final," Postecoglou said.

"I've kept my distance from the team with respect to Erick Mombaerts, the coach there, and the players.

"All those kinds of things, there'll be plenty of time in the new year after the season has settled."