Australia manager Graham Arnold says Middle East sides have closed the gap on rest of Asia

Socceroos eliminated from the Asian Cup at quarter-final stage by hosts UAE on Friday

UAE forward Ali Mabkhout al Hajeri celebrates with his teammate Bandar al Ahbabi after scoring his side's opening goal during the 2019 AFC Asian Cup quarter-final football match between UAE and Australia at Hazza bin Zayed Stadium in Al Ain. AP

UAE players greet the fans after their victory during the 2019 AFC Asian Cup quarter-final football match between UAE and Australia at Hazza bin Zayed Stadium in Al Ain. AFP

UAE forward Ali Mabkhout scores during the 2019 AFC Asian Cup quarter-final football match between UAE and Australia at Hazza bin Zayed Stadium in Al Ain. AFP

UAE's players celebrate their opening goal during the 2019 AFC Asian Cup quarter-final football match between UAE and Australia at Hazza bin Zayed Stadium in Al Ain. AFP

UAE forward Ali Mabkhout scores during the 2019 AFC Asian Cup quarter-final football match between UAE and Australia at Hazza bin Zayed Stadium in Al Ain. AFP

Young Emirati fans cheer during the 2019 AFC Asian Cup quarter-final football match between UAE and Australia at Hazza bin Zayed Stadium in Al Ain. AFP

Emirati supporters wave the national flag during the 2019 AFC Asian Cup quarter-final football match between UAE and Australia at Hazza bin Zayed Stadium in Al Ain. AFP

Japanese referee Ryuji Sato whistles for full time as players celebrate during the 2019 AFC Asian Cup quarter-final football match between UAE and Australia at Hazza bin Zayed Stadium. AFP

UAE forward Ali Mabkhout scores during the 2019 AFC Asian Cup quarter-final football match between UAE and Australia at Hazza bin Zayed Stadium in Al Ain. AFP

Players of UAE celebrate after the 2019 AFC Asian Cup quarter final match between Australia and UAE in Al Ain. EPA

Players of Australia react after the 2019 AFC Asian Cup quarter final match between Australia and UAE in Al Ain. EPA

Players of UAE greet their fans after the 2019 AFC Asian Cup quarter final match between Australia and UAE in Al Ain. EPA

A UAE fan celebrates after the 2019 AFC Asian Cup quarter final match between Australia and UAE in Al Ain. EPA

Australia's manager said Asian sides had closed the gap after the defending champions received a reality check at the Asian Cup, signalling a tough time ahead in the 2022 World Cup qualifiers.

The Socceroos once expected to dominate their regional rivals but found their title defence tough, going goalless for 210 minutes of knockout football before slumping 1-0 in the quarter-finals to hosts UAE.

Graham Arnold presided over an inexperienced and injury-ravaged squad - a far cry from the golden generation, including Tim Cahill, Mark Viduka and Harry Kewell, that he took to the same stage in 2007.

He said his young squad had much to learn, but cautioned that Asia's increasingly well-resourced teams could no longer be considered pushovers.

"You have to congratulate the UAE and Qatar - two Middle East countries that are coming very, very fast," Arnold told his post-match press conference.

"If there's anything for the Australian journalists here to take home is to look at how fast other countries are coming and catching up."

Arnold suffered injury blows to exciting Manchester City forward Daniel Arzani, Huddersfield Town lynchpin Aaron Mooy and Hibernian striker Martin Boyle before the Asian Cup, while Celtic's Tom Rogic was suspended against UAE.

Milos Degenek's defensive howler, when his back pass was snapped up by UAE striker Ali Mabkhout, was the killer blow but Australia have struggled to impose themselves, losing to Jordan and needing penalties to beat Uzbekistan.

With qualifying for the Qatar 2022 World Cup starting later this year, Arnold said an injection of extra quality would make all the difference - pointing to how Lionel Messi repeatedly wins matches for Barcelona.

"I'm not using excuses at all because the boys did fantastic but you pretty much missed Arzani and Boyle that make the difference when you play against teams with a packed defence," he said.

"Barcelona, when they do it, they've got Lionel Messi - give him the key and he opens the door. At the end of the day, those things happen. Again, these boys, it's a wonderful experience.

"We'll learn a lot from this tournament, go home, analyse the whole thing, see which players move on, if there's any retirements and get ready for the World Cup qualifiers."

Arnold, however, questioned the timing of the Asian Cup, which comes just six months after the World Cup and in the middle of the European season, giving players little chance to recover and prepare.

"If there's anything I don't understand a little bit, is why we have to play an Asian Cup six months after a World Cup," he said.

"The pressure that the players get put under by clubs to be released and those type of things is a different story.

"I've only had eight games with these boys. The style is completely different to what they've ever played. It will take time."

"Our goal is one day to be like Japan, where you can have 25-26 players at the same level and you can change players for every game."

Japan play Iran in the first semi-final on Monday, before UAE and Qatar square off a day later.