Both sides triumphed against Olympiacos and Anderlecht respectively in their Group C openers two weeks ago, and meet at the Parc des Princes where the winner would move to the head of the table.
Despite the Ligue 1 champions being the overwhelming favourites for the match, Ibrahimovic is bracing himself for a tricky encounter.
"There is a big difference from last year, because people were wondering how far PSG could go in the Champions League," Ibrahimovic told the press. "This year, all the teams know PSG with the results that we've had, and the players we've brought in.
"Teams have more respect for PSG. After a year in the Champions League, the club has more experience. We'll do all we can to win tomorrow against Benfica and show that we can be serious contenders for the title.
"They're a very good team with a lot of experience of European competition. It's not going to be easy, but we're playing at home. If we win on Wednesday, we'll have a good advantage for the rest of the group stage."
The match gets underway in France at 7.45pm.