Malthouse, with Nathan Buckley, Matthew Lappin and Glen Jakovich, is set to lead the 25-man squad into battle in a two-Test series in late October.
He said the decision to take on the role when he could otherwise have been enjoying time off was a no-brainer.
"The opportunity to represent Australia in one small capacity – and I'm not playing, I'm just coaching – is just far too good to pass up," Malthouse said as he announced the Australian squad to take part.
"I just think we get totally absorbed in our game, there's no question about that, and so we should.
"But at the end of it, there's this cherry on top where you've got an opportunity to coach Australia against the Irish, and it will probably be my last chance.
"Just sitting there and being offered the job, you don't take a lot of time to say yes."
Malthouse said the lure of wearing an Australian jumper was so great that he had a line of Collingwood players wanting to be involved in the series.
Magpies Scott Pendlebury and Dale Thomas have been selected in the squad, while Irishman Marty Clarke has been ruled out of representing his home country with an ankle injury.
"I really can't wait for the series to start," Malthouse said.
"I love coaching my young blokes here at the football club, but the next thing after a season like this is being able to talk to and relate to and understand a bit more about players from other clubs and bring them together for a series like this.
"As I've said before, next year's selections will be based totally on availability and how they perform, so they've got a chance to represent Australia two years in a row, and from then on in, who knows?
"It's just one of those wonderful things to be offered by the AFL. I'm very appreciative and honoured to think you're wearing something that says Australia on it.
"It doesn't take much to get too excited about it."
First-time representatives Marc Murphy and Nathan Foley said nominating themselves for squad consideration was fuelled by a desire to "play for your country".
"Being involved in Aussie Rules, you don't get to represent your country too many times," Murphy said.
"I jumped at the chance because you get to play with guys like Nathan and other guys from around the league, and form relationships with them.
"It's a great opportunity."
Foley, who is the only Richmond player to be involved this year, said he was encouraged by positive feedback from previous representatives.
"It's just a great opportunity to represent Australia," he said.
"Everyone I've spoken to who's played in it says it's just a great experience, and I just can't wait for the opportunity to play with the likes of Mark and Brent Harvey and blokes like that."
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The 2008 Toyota International Rules Series: Australia v Ireland
First Test – Subiaco, Perth, Friday 24 October
Second Test – MCG, Melbourne, Friday 31 October
Tickets on sale now at ticketmaster.com.au, by calling 1300 136 122 or at a Ticketmaster outlet.
For full coverage of the 2008 series, click here.
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