Take Christophe Lamaison for instance, who was arguably the dominant figure in France's surprise victory at Twickenham a fortnight ago. With only four caps to his credit, one of which was as a replacement against South Africa in Bordeaux last year, he is still waiting for the Federation Francaise de Rugby to measure him for a blazer.
But with his first ball at Twickenham, he had the gall to stand up and run around Will Carling (with 70 caps to his name) and then go on to score 18 points, made up of a full house of a try, drop goal, two penalties and two conversions. Not to mention his delicate chip kick which bounced perfectly into the arms of his winger, Laurent Leflamand, for France's first try.
So who, one might ask, is Christophe Lamaison? Originally from the small, south-west town of Peyrehorade near Dax, Lamaison, who usually answers to his Basque nickname of "Titou", joined the First Division club Bayonne as a 19-year-old in 1990. Nevertheless, despite appearing once on the reserve bench against the All Blacks in 1995, Lamaison was almost unknown in France even a few months ago, a regular if slightly overweight performer for Bayonne, just another on the list of journeymen centres who abound in French rugby.
But a change of club in the off season - from Bayonne to Brive- and the unprecedented spate of injuries in the French camp - including both first-choice centres, Richard Dourthe and Thomas Castaignede - have brought about a rapid change in his fortunes.
"A lot of people in Bayonne were upset when I left, but I know I made the right choice," he says. "At 25 years old I knew I had to take my chance. Rugby in France was about to move into a new era, and I wanted to be part of it. The train was leaving and I was determined not to be left standing on the platform."
In the space of a few months, Lamaison was transformed. For a start, Brive's all-out search for professionalism and excellence meant that for the first time in his life Lamaison suddenly started training properly. Under the eye of the club's fitness expert, the athletics specialist Bernard Faure, Lamaison has picked up a yard of pace, and shed more than a stone in weight, replacing the flab with finely tuned muscle.
"Before coming to Brive I had never once lifted weights. But I am now convinced that it is an integral part of training for any high-level sportsman," Lamaison says. "Bernard's input is extraordinary. He is able to tell exactly what is lacking in each individual player, and devise a way of rectifying it."
In short, Lamaison has suddenly blossomed and, playing outside Alain Penaud for the irresistible Brive side in the Heineken Cup, developed more and more confidence in his own ability.
It is this confidence, allied to an unfailing big-match temperament, which has enabled him to play with such aplomb as he showed at Twickenham, or earlier in Paris, when he scored one try and played a key role in setting up two others in France's 27-22 defeat of Wales. Even the 47-11 thrashing handed out to Brive by the touring Auckland Blues has failed to unsettle him. "On the contrary, it has enable me to put things in perspective. Now I have seen what top-level rugby is all about, and I know how much further I still have to go," he says.
"When you have played against 15 stone centres like the Aucklanders, coming up against someone like Carling is nothing to be afraid of."
Lamaison, like the other "ringers" who have been obliged to cover for the injuries to Dourthe, Castaignede, Philippe Saint-Andre, Olivier Roumat and Philippe Benetton, approaches each game as if there is no tomorrow. "If the others were fit I probably wouldn't even get a place on the reserve bench. I know that everybody is waiting for the injured players to return, but I am just happy to live this experience to the full. It's up to me to work harder and harder at my game so that I can become the No 1 choice, not the No 3 or 4."
To be honest, his debut in the French side was far from promising. He came on as a replacement centre against South Africa in the first Test in Bordeaux and the next week was picked as stand-off, reputedly for his ability as a tactical kicker, with the idea of keeping the Springbok back line under pressure. Many of his kicks, however, were poorly judged, and Lamaison became one of the principal scapegoats for the defeat in Paris.
"Of course it hurts being criticised like that, especially in the press," he says. "But I have tried to make use of the criticism: I have been using it as a means of motivation for me to bounce back."
After winning the Heineken Cup in January, then overwhelming Wales and England, Lamaison now finds himself on the verge of a Grand Slam. "Life is like one big party at the moment!" he enthuses. And the irony of it all seems to appeal to him: "There are some great players who have gone for 10 years without getting near a Grand Slam. And now there are upstarts like me with only a couple of caps on the point of making history. It's daylight robbery, but I'm determined to make the most of it while it lasts."
His main preoccupation in the build-up to this Saturday's game against Scotland is to hold his concentration as he did at Twickenham, and not to let talk of the Grand Slam disrupt him from the match. "I know only one thing about this game and that is that it will be very very difficult," Lamaison says. "The Scots are on a roll after their game against Ireland and we know they will come here with a lot of desire, generosity, and fire. If we can't compete with them in those aspects of the game, we'll never be able to dominate and play the way we intend to."Reuse content