The two clubs will renew their long-running feud in early 2018 with a place in the last eight of the competition on offer, having been paired together in Monday morning's draw.
Chelsea were one of the more difficult teams Valverde's men could have faced, with the Barca boss singling out attacking duo Alvaro Morata and Eden Hazard as particular threats to his side's hopes of progression.
"Tactically, Chelsea are very good and also very physical," he told Barca TV. "With Morata, they have speed in attack and Hazard is very good between the lines. They're a strong team.
"It's a hard draw for us, but we knew that nothing was going to be easy because there were very good teams in the draw.
"Chelsea are the champions of the Premier League, but we will play with enthusiasm because, although it will be difficult, it's a very nice tie for us and for the supporters. In that aspect, it's easy to motivate the players."