The Socceroos have survived a huge pre-World Cup scare from tiny Liechtenstein, scoring twice in the final 15 minutes to post a 3-1 friendly win in Ulm.

Substitute Joshua Kennedy scored in the 75th minute with a header to break a 1-1 deadlock and John Aloisi put the issue beyond doubt with Australia's third goal some seven minutes from time.

What was expected to be an easy kill for Australia against a team ranked well outside the world's top 100 was anything but.

The Socceroos had to fight back from a goal down, going behind after defender Lucas Neill's own goal in the eighth minute.

Striker Mile Sterjovski got the Socceroos back on level terms after 20 minutes but the Australians could not find a way past their plucky opponents despite many chances.

Liechtenstein, with a population of just 33,000, also had its chances particularly in the opening ten minutes of the second half.

The largely unimpressive performance will give Australia plenty to think about before its World Cup opener against Japan on Monday.

One of the few bright spots was the impressive performance from Harry Kewell who played for an hour before being substituted.

Socceroos coach Guus Hiddink wasn't surprised his team lacked sharpness just three days after their 1-1 draw against the Netherlands in Rotterdam.

"It is normal that we don't play as well as we did over there, there was a bit of a lack of concentration and we can not afford to make those types of mistakes," he told SBS.

Hiddink felt his men steadily improved as the match wore on.

"Well after that sloppy period in the beginning, we started to build up a little more pace in the second half especially with some changes on the left side and we went somewhat better," he said.

The Dutch mentor was heartened by Kewell's continuing recovery from a groin injury but felt the Liverpool star must improve before meeting Japan.

"We planned to play him an hour so he can practice again tomorrow and the day after so I hope bit by bit he recovers his strength because you need to be fit," Hiddink said.

"He did a rather good job but still has to find another 20 to 30 per cent more strength."

Brought to you by AAP © 2024 AAP