Gerry Thornley talks to flanker Keith Gleeson who always believed he would make it at international level - playing for Australia, the country he plays against today for Ireland

He's driven, ultra professional, almost obsessively single-minded, highly intelligent and utterly self-assured. The last person to doubt whether Keith Gleeson could make it at international level was Keith Gleeson.

The irony is that today it's against the jersey he used to dream about and believe it was his destiny to wear. It's as if his whole career pointed toward this day. A Holy Grail of sorts.

Ireland-born, Australia-reared from the age of seven to 24, he's had to rediscover his roots to prove himself at this level. He wouldn't be human, therefore, if he didn't see this as the biggest game of his life.

Aside from the fact his folks back in Sydney will be watching the game, invariably there'll be a particular curiosity factor about his performance back in Oz. The spotlight's on him more today, and it's a chance to prove himself to some doubters back there.

As regards his seven caps, Gleeson is the type of realist who only counts the two full caps against the All Blacks as truly worthy of the name. So, not that he'd necessarily come out with the usual clichéd claptrap about this being "just another match", you ask him not to lie about it anyway.

"It's certainly not another match and I'd be lying if I said I didn't want to prove myself. To myself yes, but more so to perhaps show other people that yes, I was good enough, if only the opportunity had come."

Not that he'd be the time of bloke to be riddled with self-doubts. Deep down, Gleeson always felt he was good enough to play at Test level, never mind Super 12 or provincial level. Returning to the land of his birth was all about proving that point.

He could see it, it's just that others couldn't.

Had that alternative route into international rugby not existed, he would simply have stopped playing, and had he not proved it within these first two seasons with Leinster, his career would voluntarily have come to a full stop. A high achiever, Gleeson is not one for setting his goals too low, and playing Test rugby has been a dream since he was a little boy.

Gleeson has already worn Aussie gold at under-19 and under-21 level, underlining his innate leadership credentials when captaining the latter.

"I'd say, without a doubt, when I was captain of the under-21s we won the SANZAR tournament, stands out. We actually won it two years and in the second year I was captain, when we beat South Africa, Argentina and New Zealand, as well as Ireland under-21s the week before, was a very enjoyable feat and accomplishment."

Current Leinster coach Matt Williams was his mentor to a large degree, bringing him into the New South Wales Waratahs fold, though holding him back until the last couple of Super 12 games and the win over Ireland in Williams' last game in charge.

Further frustration followed, though, when Ian Kennedy and Bob Dwyer in turn overlooked him.

"Certainly I didn't get the opportunity. The most staggering statistic which worked against me in my four years in New South Wales was that there was never an injury in the back row. Coaches will always have their views on picking the players they want but most players in general get a game through injury somewhere along the line.

"In the four years I was at New South Wales there was never an injury until the very last game. I played in that last game but by then the decision had already been made to head overseas to Ireland as there obviously wasn't any point in staying in New South Wales at that stage."

With a business degree, there's no doubt that the high achiever in Gleeson would most probably have retired at 25 to join his father's financial services' business but for the Leinster offer. It is perhaps that plan B, as well as his rearing, which explains Gleeson's streak of independence as regards the game.

"I think I seriously would have considered retiring if the Leinster offer hadn't come in because I don't think I was really interested in going to play in Europe just for the money. There had to be something else there, the chance to play international rugby. A chance to do so playing in Dublin was what it was all about."

Not that his self-belief left him nor, now, will he ever retire wondering whether he gave it his best shot.

"His work ethic is world class and he's the ultimate professional," says Williams. "There's not a stone left unturned in his preparation and the other thing is he comes from a Jesuit school and is an academic."

In their New South Wales days Williams used to joke with Gleeson that, because of their backgrounds, one day they'd both end up in Ireland. The summer before last he rang Gleeson to say it was no joke anymore.

"It took about an hour - two phone calls - and I knew it would be. And once I was here, I also knew it was made for him."

Gleeson is a true openside, a groundhog and a linkman as opposed to a runner, and has fitted Leinster - with their wide, attacking, continuity game - like a glove.

Gleeson blames his Celtic bloodline for his late physical development.

"He's not a small guy but for an international forward he wasn't huge, and he had to build up," Williams explains. "And it was the Celtic bloodline. It's a fact. Australian schoolboys or under-21s always get walloped by New Zealand 99 per cent of the time because they have Maoris and Polynesians in their teams, and they mature physically at 18 or 19, and Celts mature at 24, 25. That's just genetics. And it's very difficult telling a highly intelligent, highly academic, keen as mustard 22-year-old that he's got to wait another three years."

While acknowledging he was frustrated by Williams' selections at the beginning in hindsight Gleeson now accepts that there were a couple of factors working against him.

"Australia and a lot of the world were still playing very big back rows. The game was slightly different and there wasn't a need for pace to get to the ball, until David Wilson really established himself and I do blame the Celtic blood for not coming through as quick as I would have liked but maybe the same thing prolongs my career and allows me to play until I'm 30 or 31."

Others might have been deterred at the prospect of additional hours in the gym every week for years, but not Gleeson, who accepts that he's a very driven individual.

"I do have aims and plans, in rugby and in my lifetime. There's certain things I like to keep to myself but yes, I do know where I want to go in rugby and to a certain extent in life. That's not always so clear."

Williams detects that not only has the belated international opening been good for him, but the home Dublin scene (his cousin Ciarán owns Gleesons pub in Booterstown) and especially the more irreverent Leinster set-up has been good for him too. Not a wild child, more a self-confident academic, he's been taken at face value while having a few spots knocked off him.

Gleeson reveals that on his last trip home to Sydney during the summer his mother observed how much happier he seemed and Williams concurs.

"I sense a much greater calmness and happiness in himself since he came to Ireland. A lot of that is he's finally getting an opportunity to fill his potential."

The flip side of his earlier years of frustration and late development is that Gleeson is a relatively low-mileage 25-year-old. The Celtic bloodline should ensure a longer endgame.