Ibrahimovic has scored 18 goals in 33 appearances for Barca this season, but the former Inter Milan, Juventus and Ajax star failed to make any impact when Milan crashed out of the Champions League to Liverpool and Manchester United in the previous two seasons.
However, he is adamant he has nothing to prove after winning six league titles in the last six seasons.
"I think I haven't performed my best in games against English teams," Ibrahimovic admitted.
"But the last time was with Inter against Manchester United and it is harder playing for Italian teams against English teams because Italian teams are more concerned with not conceding.
"Obviously Barcelona saw what they bought. I had five fantastic years in Italy and played in Holland before that.
"The people who know football know the way I can play and I don't think I have to demonstrate that to anybody.
"I have six league titles in a row so I don't know how much more I have to prove after that. But I came to Spain to win more important titles and keep improving myself.
"When people criticise you, you hear it from somebody even if you don't read it, but the biggest criticism is from myself. I have had hard times but I'm playing well now.
"Barcelona's mentality is always attack, attack. It is very important to score an away goal and if we can win that would be great. At home or away we always try to win.
"I think Barcelona are the favourites because we are the European champions. Wherever we go we are the favourites. We have a good team who can win whoever we play."