The Gunners were knocked out at the quarter-final stage by the same opponents last season after they were largely outclassed by the Catalan giants over both legs.
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But Iniesta, who scored Spain’s World Cup Final-winning goal against the Netherlands last summer, insists that Arsenal will pose more of a threat than they did 12 months ago.
"People speak about the matches last year but things are completely different,” the 26-year-old told reporters.
"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 are not a machine. It won't be easy. This isn't a walk along the promenade for us.
"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."
Barcelona are currently five points clear of Real Madrid at the top of La Liga having lost just one league match all season, scoring 71 times in the process.
Lionel Messi has taken the plaudits for Pep Guardiola’s side this campaign but Iniesta says the success of the team is not down to just one man.
"Leo is enormous. What he can do surprises no one. It's easy to play with him and that's a big virtue," he said.
"But the success of Barcelona is the team effort. We are top of La Liga, going well in the Champions League and believe in ourselves.
"The squad is functioning perfectly but it's a question of work, work and more work.”
By Joe Whitbread
