The Italian outfit are strong favourites to reach the quarter-finals of the competition thanks to a 3-0 victory that they achieved during the opening leg of their tie away at Celtic a fortnight ago.
However, despite almost being in the last eight, Pirlo has admitted that there are "stronger teams" in the competition than his side.
"The Champions League? I don't think that we are ready to win it yet. Even though we're there now and will do our utmost. There are stronger teams than Juventus still in the competition," Pirlo told La Repubblica.
Juve last won the title back in 1996.