AUSTRALIA captain George Bailey is challenging his side to lift after accusing them of being flat in their World Twenty20 warm-up game against England.

Bailey is confident Australia's "A" game will be enough to overpower Ireland in Wednesday's Group B clash in Colombo.

Australia were runners-up in 2010 in the West Indies but have shown patchy form and have a world ranking of No.9, only one place above the semi-professional Irish.

Defending champions England scored 6-172 on Monday to notch a nine-run win against Australia who conceded 14 wides and generally showed a lack of intensity that needs to be corrected in a hurry, Bailey says.

"Australia are our biggest threat," Bailey said on Tuesday.

"If we rock up ready to play and play as well as we can (against Ireland), then I don't think there's a threat."

Bailey admitted his side lacked a certain something against England.

"It's not a format where you can afford to do that because 20 minutes of flatness and dead energy can cost you a game, knock you out of the tournament," Bailey warned.

"Hopefully you won't see that again."

Bailey said his side have had an excellent preparation including a three-game T20 series in Dubai against Pakistan in September plus warm-up games against New Zealand and England in Colombo.

"I'm pretty confident. The last couple of weeks I think have been great for this team to spend some time together," he said.

"Once you understand how the guys around you are going to play you have that real structure in your head and you've got a real sense of what the team's going to do.

"It feels like the team really grows a leg."

Bailey, who made his debut as player and captain in 2012, says he's relying on vice-captain Shane Watson and ex-skipper Cameron White to give him tactical advice during the helter-skelter of T20 matches.

"The game happens so quickly and there's so much going on that quite often there will be things that I'll miss and there'll be things I won't have time to focus on," he said.

Bailey has dismissed concerns that his side lacks match-winners beyond their top order of Shane Watson, David Warner and Mike Hussey and opening bowlers Mitchell Starc and Pat Cummins.

Bailey says wrist-spinner Brad Hogg, at the age of 41, is another big wicket-taking threat.

"Having six or seven guys who can win a game and hopefully two or three come off each game so you don't rely too heavily on one guy for three or four games (is important)," Bailey said.

"That makes us really dangerous.

"We want to hit the ground running as much as we can, so that sends our momentum through the roof and other teams take note of that."

Originally published as Aust have nothing to fear, Bailey says