Primera Liga leaders Barca lost 2-1 against Espanyol on Saturday, only their second defeat of the campaign. This followed a draw last week with Real Betis.
"We haven't secured good results in the last few days but we are not suffering any doubts. We are confident in our abilities and know the route we want to take," captain Carles Puyol said.
"It's always painful to lose and the dressing room's down, but are looking forward to getting into the next game as soon as possible."
Coach Pep Guardiola may use Puyol at left back to cover for Eric Abidal who has been ruled out for eight weeks after picking up a groin injury against Espanyol.
He is also without injured midfielder Andres Iniesta so Seydou Keita could step in as he did against Espanyol.
Ligue 1 leaders Lyon won 2-0 at Nancy on Saturday with the seven-times champions partially resting key players Juninho, Ederson and Karim Benzema.
"This victory is good for our morale and confidence," said centre back Cris.
"It's always important to win your league game before a Champions League match but the Barcelona game will be a different story," added midfielder Juninho.
Cris, who netted Lyon's first goal at Nancy, said Barcelona's weekend defeat would have no bearing on the tie.
"It was a Spanish league game and we will be playing in the Champions League," he said.
"I watched yesterday's game, it was a derby, there were a lot of yellow cards, the Champions League is totally different.
"Barca is another competition. It's a dream for everybody but we are ready. Everybody has in mind that it will be very tough but we know we can achieve something."
Lyon are still deprived of defenders Francois Clerc, Anthony Reveillere and winger Sidney Govou, who have not yet fully recovered from long-term injuries.
The seven-times French champions, who will play in the last 16 for the fifth season in succession, have never made it past the quarter-finals in Europe's premium competition.
Probable teams:
Lyon: 1-Hugo Lloris; 11-Fabio Grosso,3 Cris, 4-Jean-Alain Boumsong, 15-John Mensah; 28-Jeremy Toulalan, 8-Juninho, 6-Kim Kallstrom, 7-Ederson, 19-Cesar Delgado; 10-Karim Benzema
Barcelona: 1-Victor Valdes; 20-Daniel Alves, 3-Gerard Pique, 4-Rafael Marquez, 5-Carles Puyol; 24-Yaya Toure, 15-Seydou Keita, 6-Xavi; 10-Lionel Messi, 9-Samuel Eto'o, 14-Thierry Henry
Referee: Wolfgang Stark (Germany)
