Lyon memorably toppled Manchester City at the Etihad Stadium in September and twice led the Premier League champions during an entertaining 2-2 draw in the reverse encounter.
"The truth is that I have seen little. I have a general idea, there are some players that we know, but we have to prepare well," Valverde told his club's media channel.
"It's a team that was challenging City for leadership of the group until the last game and won at their ground.
"That shows the difficulty to win any game. Not only for us, but for any team.
"I have the sense they are a very dangerous team in space because they break very well, very fast, and we have to be a little careful.
"We can't afford to be complacent. We have two months to refine ourselves a bit more, to study the opponents more and get to the tie in good shape."
Barca, three points clear in LaLiga, are aiming to improve on three straight quarter-final exits in the Champions League.
Fellow La Liga outfits Real Madrid and Atletico Madrid were also involved in the draw, with the Galacticos given an interesting encounter against Ajax, and Diego Simeone’s side dealt a tough encounter with Serie A champions Juventus.
Manchester United and Liverpool are both involved in the two most eye-catching matches of the last 16 draw. The Red Devils will play Paris Saint-Germain, whilst Jurgen Klopp’s Reds face an intriguing tie against Bayern Munich.