Australia needed extra-time and then penalties to get past the White Wolves and reach the quarter-finals.

The tactical approach employed by Uzbek coach Hector Cuper caught Arnold unawares, with the central Asian nation enjoying some success playing on the counter.

"You've got to give credit to Uzbekistan, who fought hard and long in the game, made it very difficult for us to break them down with defending so deep," he told reporters.

"I have to say I didn't really expect that, that would defend so deep. We struggled with the final pass. I've been in charge of this team for only four months. We've changed the style and we expect to imrpove in every game that we play.

"We've showed it in glimpses but, as I said, Uzbekistan made it difficult for us."

The Socceroos will be without Tom Rogic for the quarter-final against the UAE after he received a yellow card.

Arnold described the caution as "a bit harsh".

"The yellow card was a bit harsh because Tomi had no intent," the former Sydney FC coach said.

"He just had the ball at his feet. These things happen. We have the options and I can change the system if we need to...

"I could change play with two strikers, two number nines, we could play with a diamond midfield."