To see the Olyroos training at Bluetongue Stadium...

"The problem is we have no FIFA power with over-age players. We have to have the blessing of the club and the blessing of the player to come along," Arnold said after training at Bluetongue Stadium.

"At this moment, players I do have on the radar have other problems.

"Every Socceroo has a chance. Obviously, players have different problems; changing clubs. That makes it a bit more difficult but I've got a few weeks to think about it.

Arnold described his Olyroo defence during the arduous AFC qualifying campaign as "exceptional", singling out Mark Milligan and Adrian Leijer, but admitted he needed firepower in the final third.

"It's got to be someone who can make a difference, change the game and add some quality," he said.

"I'd love Harry to come but he's got to sort out his own personal future. And we'll react to that situation when Harry makes his future known."

As for Schwarzer in goals for the suspended Danny Vukovic, Arnold is again keeping his options open.

"I've still got Adam Federici who's under-age to come in, so I'm pretty happy in the goalkeeping department but it's good to know that if need be I can fall back on Mark Schwarzer."

Arnold added that whoever comes into the squad from Socceroo ranks would have to "fit into the chemistry of the team. He's got to fit in with the group."

The Olyroos will play Japan, China and South Korea in July as their preparations continue for Beijing in August.

To see the Olyroos training at Bluetongue Stadium...