Sarries will first face the Top 14 outfit at Allianz Park on Sunday before they travel to France to take on the same opposition seven days later.
Clermont will be familiar opponents for Saracens, as they beat the French club in the final of the same competition last season, although Sarries will head into this week's contest having lost their last five domestic games.
However, despite their recent struggles, England international Barritt remains confident Saracens can maintain their impressive European record, although he is under no illusions just how important the doubleheader could prove to be.
"It's a pivotal two weeks in the tournament for us," Barritt told the Daily Mail. "You come out on top in terms of net points over the course of both games it's going to put you in the strongest position in the pool.
"We know it's make or break for us in terms of our Champions Cup route, so we are going to put all our focus into them."