Andres Iniesta is wary of the threat Arsenal pose to Barcelona's UEFA Champions League dreams.
The Catalan giants are set to face the Gunners in the last-16 of this season's competition, in a re-run of a quarter-final clash from the 2009/10 campaign.
Barca emerged victorious on that occasion, claiming a 6-3 aggregate success, and are well fancied to prolong their continental adventure this term.
Iniesta, though, insists Pep Guardiola's Primera Liga leaders are not 'invincible' and admits they will need to proceed with caution as they prepare to visit Emirates Stadium on Wednesday.
The Spain international said: "We are not a machine. It won't be easy. This isn't a walk along the promenade for us.
"But Barcelona never take the field looking to be arrogant. That would be an enormous error.
"People speak about the matches last year but things are completely different.
"No two games are ever the same and we are aware Arsenal will be very motivated this time. That makes them even more dangerous.
"Barcelona aren't invincible and going to London is risky.
"We can win the first match but we face a battle to stop Cesc Fabregas and a team which will want to show its very best against us."
Gunners skipper Fabregas continues to be strongly linked with a return to his Catalan roots in the not too distant future, but Iniesta is keen to steer clear of that subject for now.
He said: "The future of Cesc depends on the teams and we accept their decisions. For now he is the leader at Arsenal but we are not obsessed about him.
"The Gunners have an excellent squad and it will be an error for us to forget about the others."
While Iniesta is in cautious mood ahead of a midweek meeting with Arsene Wenger's men, his midfield colleague Pedro insists Barca will stick to their positive game plan when they arrive in North London.
He said: "It will be a nice, open game where we hope for a good result.
"We're going out to win. Getting a decent result in the first leg is always good. We aim to do that and finish it off at home."