The first-leg will be held on Thursday night.
“We know this is an important competition and we want to go all the way," said the Spain international midfielder in his press conference.
“Barcelona are strong, but we are doing well too and hope to win tomorrow. We like to have control of the ball, hold possession and dominate the game, but Barcelona play the same way. We'll see who gets more of the ball.
“We know that Barcelona are going out there to win, but so are we. We prepared with hunger and hope to bring home a result, even if we know it's going to be difficult.
“They made January signings, it's a home and away tie and hopefully having the second leg at home can be a slight advantage.
“It's not right to say Barcelona today are less frightening an opponent than in the past, as they have great players.
“I don't know if Napoli are among the favourites to win the trophy, but we are a strong team and want to challenge as far as possible."