Laurent Blanc's side have made a slow start to their title defence in Ligue 1, winning one of their opening three matches.
Ibrahimovic believes that PSG need time to adjust to a new regime under Blanc, while conceding that even retaining their domestic crown might not be enough to constitute a successful season.
He said: "We are still learning how he wants us to play. It is the beginning of the season and we are struggling a little bit, but it is in these moments we learn the most.
"There is a lot of pressure around him at PSG because of the investments we have made, and we share it with him. We have high hopes, because I don't think only one trophy would satisfy our owners."
Summer signing Edinson Cavani is likely to partner the Swede in attack tomorrow night, as Blanc's side look for a first home victory of the campaign against Guingamp.