Keith Duggan talks to Ireland's openside flanker, Keith Gleeson, who not so long ago was captain of the Australia under-21 team

Every Wednesday, Keith Gleeson eats lunch with his grandfather in the family pub in Booterstown. For two decades, his grandfather was this cheerful voice on a whistling phone line, a familiar Irish accent travelling through the hemispheres from a place of which he could just about summon misty memories. Growing up in Sydney, his grandfather's clear and sonorous brogue was Ireland.

So these weekly meals, they are his way of watching the animated face that goes with the cadences. It is the Gleeson men's way of getting to know each other all over again in the absence of the bridging generation - Keith's father, Tony. Although naturally talkative, the younger man finds himself asking questions and then listening. There is so much to know. He asks after his grandmother. He thirsts for more knowledge about his father's childhood in the city. He is curious about the country itself. What was de Valera's Ireland like? How did you live then? What was it like to be young?

"I just love hearing him talk, and learning about my family and Irish heritage," Gleeson explains. "And there is a lot of wisdom to be gained by speaking with older people."

But for - well, take your pick - luck, talent, opinion, circumstance, fate - Keith Gleeson might have worn the green and gold of Australia on the famous, soaking day at Lansdowne Road last autumn. Like big Owen Finegan, he might have been playing for the world champions against the team of his father's land, the likeable and hot-headed Celts who seemed to reserve their passions for Australia.

Not so long ago, his intention was to be a Wallaby. Not so long ago, Keith Gleeson was captain of the Australia under-21 team and was biding his time until a chink of light appeared on the senior landscape.

"Well certainly, I remember a time the president of the ARU (Australian Rugby Union) walking into one of our team meetings and he told us to take a good look around because of everyone sitting here, only two would become fully-fledged Wallabies. And I was looking around wondering who the other guy was gonna be."

He laughs when he tells this story and shakes his head but uses it as a cautionary tale as well. At 26, he is hardened to the vagaries of professional rugby and shudders at the notion of kids who dream of being the next Brian O'Driscoll, the next Stephen Larkham. The percentages argue against it.

Keith Gleeson is on the world stage, if not exactly cast in the role he once imagined himself in. But he is not a million miles away either. He does not see his recently dissolved hopes of playing for Australia as being totally incompatible with the pride he will feel tomorrow at Lansdowne road. For his background has always crossed the two cultures.

Gleeson was in First Communion class when his parents decided to bolt.

Tony Gleeson was doing pretty well in 1981 but he and his wife Diane read the storm clouds and didn't like what they saw. The government was flailing and Gaybo was daily predicting on the radio that the country was going down the tubes and Aer Lingus was doing brisk one-way business to New York and Down Under. Thousands were sailing and the Gleesons joined the exodus. Travelling was in their blood anyway; Tony met Diane when she was back-packing around Canada, where he was working as an accountant. They spent a decade there before relocating to Dublin.

"So moving to Australia was more to do with us," says Keith. "I think they felt that after college, myself and my brothers would end up emigrating anyway and they didn't want the family split up. So they moved somewhere we could all stay."

The big move was like a late-night adventure when you were seven and Gleeson fuzzily recalls being passed around for fierce hugs at the airport gates and an eternal plane ride to his new home.

"As a kid, what you want to do is fit in straight away. And arriving in Sydney with this piping Irish accent got you noticed straight away. And not always in a good sense."

So Gleeson did what kids do. He played games.

Cricket: "A disastrous idea. Not suited to my temperament.

Basketball: "I loved it. I still think it is the reason that I have got fairly good hands."

And rugby: "Yeah, rugby."

The weird thing was, he never realised he knew the words to Flower of Scotland until Murrayfield last month.

"And I'll openly admit that I partially sang along with their anthem for a while. Because Murrayfield is where you dream of playing as a kid and hearing that anthem sung in such a setting was incredible, it really was."

Call him a ham, but he might just hum along to the brassy, upbeat Gallic national song this afternoon as well.

Playing France at Lansdowne Road: it is a milestone for Keith Gleeson. Australia gets limited exposure to Six Nations but he was well versed in the lore of the competition through his father and they would trawl the Irish neighbourhoods for live broadcasts during the Antipodal summer nights.

When Gleeson accepted an invitation from Matt Williams to join Leinster in 2001, it was with a view to joining the Six Nations club. Australia, he knew, had quietly - and imperceptibly - passed him by.

Stirling Mortlock and Jeremy Paul, those two guys were in the classroom at that ARU meeting. The chosen ones. So Gleeson retraced his parents' steps and set forth for Dublin. Ireland coach Eddie O'Sullivan's words best describe how the ex-pat said hello to Irish rugby.

"Well, he really burst on the scene with Leinster and kind of forced himself into the squad last year at the end of the Six Nations. In New Zealand then, he played out of his skin. He is a world-class groundhog openside, he has got his hand into everything going. And he plays with such intelligence. At the moment, he is at the top of his game. I mean, we have a lot of competition in that position but to be fair to Keith, he got his chance and by God, has he taken it."

Burst. Force. The verbs are significant. Gleeson has an unstoppable energy about him, a friendly and outgoing and awesomely collected 26-year-old. He already has a commerce degree and a financial planners' course behind him and offers a stern lecture on the importance of education for wannabe rugby stars. His is a fickle sport but he loves it and for the next four years, his aims are simultaneously simple and grand.

"I don't think there is any point in playing unless I can at least try to be regarded as being one of the best in the world in my position. That's a couple of years off but that's the aim. I suppose right now, it's a case of judge me after the Six Nations and then I will have a better idea of where I stand in the Northern Hemisphere."

Now, it is Gleeson's turn to make the trunk calls to Down Under. He has a wonderfully complex and honest attitude to his adopted country.

"The first thing you copped was the Irish-bashing jokes when the Irish economy wasn't doing well and we were the laughing stock of the world," he will recall of his early impressions of his adopted land before explaining, minutes later, "I love Australia. It is a great place to grow up. Australia offers so much."

It would be flattering to think that in five years, the Aussies will look wistfully at Gleeson and admit he was one that got away, one that left the room.

"Only time will tell," he says.

For the present, Australia is in the past. Gleeson has a wonderful expression for his current life that he took from Matt Williams.

"He always says it is the 'one crowded hour' that we look forward to. The game."

The rest is preparation and waiting. Training and swimming and movies and Gameboys and light reading. Pressed, Gleeson admits his own bodice ripper of choice is Martin Gilbert's History of the Twentieth Century.

Why not? Migration must be a theme central to the text as well as to Gleeson's own heart. Some 70 years ago, his grandfather played in a schools rugby final at Donnybrook. Decades later, his own father did and now, it is his club home with Leinster. All of this he has only discovered recently and with each step forward, he learns more about what has gone before.

Tony and Diane will be in a steaming, noisy Sydney Irish bar at 1.0 a.m. to watch their middle boy doing his thing in Lansdowne Road. Groundhogging, as the coach would say. Playing out of his skin. Singing both anthems.

In true Australian fashion, the Irishman went walkabout and has come full circle.