MADRID - FC Barcelona coach Ernesto Valverde admitted on Tuesday that his side needs to improve if they are to seal their place in the knockout stage of the Champions League when they entertain Borussia Dortmund on Wednesday night.

Barca may go into the game as leaders of their group and as well as in the Spanish Liga Santander, but recent performances such as Saturday's narrow 2-1 win away to bottom of the table Leganes have seen Valverde's side struggle to produce the form of the team in recent years.

"You always have to improve, we are the club that we are," explained Valverde in his pre-game press conference.

"The demand is for us to show a lesson in football in every game we play and our aim is for the team to win and the people to be happy with the performance."

A win for Barca will assure their place in the next round, but defeat would leave them needing to avoid defeat away to Inter Milan in the last game of the group stage.

"It's obvious it's a vital game for both sides, we have an advantage and a chance that we want to take. We will be in front of our fans and we are strong at home, but Borussia will come here to give everything," warned Valverde.

While Barca has struggled away from home, they have not lost in the Camp Nou in their last 28 games and the coach admitted they had "problems" on their travels. "However, right now we are thinking about assuring first place in the group," he assured.

"This is a great opportunity for us to qualify and any of the other teams in the group would like to be in our position," commented Valverde, who was also asked about his side's style of play.

"The best way to win is to create chances and that your rivals don't create any. We will try and get the result through the football we play. Against Leganes we created two goals through set pieces that we created. Our aim is always to attack," he insisted.