Jordi Alba acknowledges that Barcelona cannot afford to take Celtic lightly in their UEFA Champions League clash.
The reigning Scottish Premier League champions face a daunting trip to Camp Nou on Tuesday.
Celtic will head to Catalunya buoyed by an away day success over Spartak Moscow in their last European outing, with that result taking them onto four points from two fixtures.
Barca struggled to a 3-2 victory over Spartak in their opening Group G encounter and Alba agrees that Tito Vilanova's side will need to raise their game if they are to safely negotiate another potential banana skin.
The Spain international said: "We know it won't be easy against Celtic because we have already suffered at home against Spartak when they came close to winning.
"We don't want to repeat the experience against the Scots.
"We know if we can get the six points in these next two games against Celtic, it will secure our passage into the next round.
"Of course, we're big favourites in this group and we're prepared for that role. It doesn't affect our performance but it does increase the effort of our rivals."
Alba added: "Everyone knows Spanish football is superior to Scottish football but we respect Celtic as they have defeated Spartak in Moscow and we almost didn't beat the Russians in Barcelona.
"I didn't expect Celtic's win in Russia but that has given them belief they can also qualify.
"That is a warning to us not to be too confident. We have watched some of Celtic's games already and they are a good team, who are always looking to exploit mistakes and take their chances."