"We know we are in for a big clash and that the game is vital if we want to qualify for the quarter-finals," he said. "If we lose at home against the Ospreys that will be it, we will be out. There is no room for error, we can't afford to lose.
"I think defence will be a key point for both sides and in Round 2 we had a taste of just what tough and fierce opponents the Ospreys are. They are a complete side with powerful and mobile players up front and a fast backline who enjoy playing out wide - they are good at piercing defences and scoring tries.
"The game in October finished with a really tight score to them of 25-24. We were too slow starting and they put a lot of pressure on us, they smothered us and we couldn't impose our game in the first half.
"We managed to get back but it was a really tough match. They have so many quality players and also plenty of international experience.
"As for their backs and looking at how they play, Barry Davies, Nikki Walker and Tommy Bowe must spend a lot of time training on support, especially Davies as he is a bit more powerful than when he was with Brive.
"They also have very good handling skills and are really keen to get their hands on the ball. All this talent and the hard work they put in is proof the team is serious about the job.
"We have a lot of talented players and we also like to run the ball. In the games against Leicester, it was a real treat because we got to express ourselves on the field. It did us a lot of good and allowed us to play this Heineken Cup
campaign on a better note.
"It will only be when each player takes more individual responsibility that we will progress as a group and be able to go further in this tournament.
"I was rested for last weekend's Top 14 16-15 win at Toulouse due to long-lasting minor glitches and to avoid any potential complications. The staff wanted to have a turnover in the squad anyway so it was ideal for me to have a break.
"We are already suffering from the absences of Jason White and Julien Bardy who sustained tibia and fibula fractures respectively so we did not really start the new year on the right foot and let us hope the number of long-term injured players will not increase otherwise we will struggle to finish the second part of the season."
Clermont have not qualified for the Heineken Cup knock-out stages since the 2001/02 season but they are double European champions after winning the Amlin Challenge Cup tournaments in 1999 and 2007.
"So far my best memory in Europe remains our victory in the 2007 Challenge Cup final against Bath," said Rougerie.
"That was a great moment because although we generally do well each season in our domestic championship, we had been struggling for a number of years to win any silverware and that trophy was most welcome. We have been surfing on that good vibe ever since and we always try to find our inspiration from that experience to keep a positive spirit."