The Ligue 1 outfit host the first leg of the tie on Thursday, having negotiated their way past Viktoria Plzen in the previous round, before a return trip to Turin in a week's time.
Garde is under no illusions as to the magnitude of the task that lies ahead, with the Scudetto holders sitting eight points clear at the summit of Serie A, though they were beaten by Napoli on Sunday.
"We have a mountain before us and should try to climb it by all means," the Lyon boss told reporters.
"My players are young, but they are ambitious and this kind of game will make them grow."
Lyon midfielder Steed Malbranque echoed those comments while demanding that the team do not settle for a last-eight finish, and suggested that the fixture was worthy of an even greater stage.
"This is a game that looks like the Champions League against a big team, a formidable adversary," the Frenchman said. "We must not be satisfied to reach the quarter-finals.
"I know that the players who will be lined up tomorrow will do their utmost to achieve."