Thierry Dusautoir comes across as the mild-mannered type, soft-spoken to the point of being shy when he is outside the playing arena.
Then there is Dusautoir the France captain, who morphs into a ferocious tackling flanker whose actions speak louder than words.
"Before a match, I think about the battles ahead, the rhythm," he said in an interview. "I expect my head to spin, my heart to beat at 2,000, to no longer know where I am."
One of the rare times he has taken a public stand off the field was in defence of Marc Lievremont when the France coach came in for criticism following a defeat to Italy in the Six Nations championship in March.
With voices of discontent growing louder, as the domestic media criticised Lievremont, and as rumours abounded that there were rifts forming within the French camp, Dusautoir decided it was time to show his colours.
He rallied the players behind the coach and they have patched up their differences. Now their focus is on the Rugby World Cup.
"I think we can go far. The most important factor will be how we go about making this tournament our own, so we have no regrets afterwards," Dusautoir said. "The team will become like a substitute family. In a way that's good, because it will bring the squad closer together."
France won their two warm-up matches against Ireland, 19-12 in Bordeaux and 26-22 in Dublin, and Dusautoir is optimistic that the team's form is improving.
"We're going to get better and better," he said. "It's good to see where we stood with regards to Ireland. We know what we need to work on to improve."
Dusautoir, 29, has won 44 caps since making his debut against Romania five years ago, and is widely respected on the international scene.
In June 2009, he guided France to their first win on New Zealand soil since 1994, and to an impressive home victory against South Africa, the World Cup champions. A year later, he led France to the Six Nations title and the Grand Slam.
But all that came after Dusautoir truly made his mark on a special night in Cardiff during the last World Cup. Dusautoir, who was only called up to the 2007 World Cup squad as a replacement for Elvis Vermeulen, stood out by making more than 30 tackles against the All Blacks and scoring a decisive try as France rallied to win an epic contest 20-18.
It was a stunning performance from a player making only his eighth international appearance.
"We were on another level during that match," said Dusautoir, who grew up learning judo.
Dusautoir waited until he had completed his studies in chemical engineering before playing rugby full-time for Biarritz in 2004. He was soon scaring the most intimidating opponents in French rugby.
Fabien Pelous, France's all-time record holder for appearances with 118 caps, recalls being on the receiving end of one of Dusautoir's huge hits during a French league match. "I remember a tackle that hurt me. He was playing for Biarritz, I didn't know who he was," Pelous said. "When he signed for [Toulouse] I was happy because he's a player you would rather have with you than against you."
While he has earned the respect of everyone in the domestic league, he is determined to expand on that at the World Cup, where he is hoping to become the first France captain to win the trophy.
"New Zealand is the motherland of rugby," he said. "The team that manages to become world champion over there, that manages to win on All Blacks soil, will gain more respect than all of those who came before them."