However, Rougerie knows that experience will count for nothing and has highlighted the threat Roberts poses to Les Bleus, believing him to be the man that gets Wales ticking.
And the 6ft 4" centre praised the youthful look of Warren Gatland's squad on a whole, believing it is a similar model to that which has helped his club Clermont become one of the forces in the Top 14.
"Roberts is a great player. He makes them go forward each time he touches the ball," said Rougerie
"He is one of the centrepieces, if not the centrepiece, of his team. Wales rely on him to a great extent.
"His physicality represents a big challenge to us and we need to prepare properly against him. So far Wales have been very impressive, they have shown a disconcerting fluidity and looked dangerous.
"I come from a club where we believe in identifying young players and giving them their chance so it is no surprise to me to see the young Welsh players come in now and do so well.
"I know how quickly young players can make an impact if they are coached properly and given the opportunity at the right time."