Barcelona midfielder Seydou Keita feels shutting out Chelsea at Camp Nou on Tuesday will stand them in good stead to win the UEFA Champions League semi-final.
Barcelona have kept eight clean sheets in their past 11 games and the Malian international believes another is crucial if they are to make it to the final.
"It's very important to win and not let a goal in," said Keita.
Barcelona are still fighting for trophies on three fronts, but Keita insists that Chelsea are their only concern at the moment, with manager Pep Guardiola preparing for the Blues meticulously.
"They are an opponent we know well, they are a great side. We've seen how they play in both the Premier League and the Champions League.
"They are a difficult team, with physically strong players, and a team who are capable of causing you problems at any time."
Keita was also quick to add to the widespread praise interim Chelsea manager Guus Hiddink is receiving at the moment.
"The coach does a great job in preparing for matches. We see a lot of their games and we analyse their weak points and the dangers they could pose to us."
Keita is confident that Barcelona will progress and says the squad are relaxed ahead of the game.
"The team is very calm because we are working well."