Please Wait . . .
A first-half brace from Serge Gnabryand Robert Lewandowski's 55th goal of the seasontwo minutes from the end sealed the victory as Bayern stayed on course for a first treble in seven years.
"We knew it would be difficult, they came in off the back of great performances against City and Juventus," Flick told Sky after Bayern won their 10th consecutive Champions League game, equalling the longest streak in the competition's history.
"They are strong tactically and they caused us problems early on. We know we need to defend better, we said before we couldn't afford to give away the ball easily, but we did."
Thomas Tuchel's PSG, who will look to the likes of Neymar and Kylian Mbappe for inspiration, will feature in their maiden Champions League final after outclassing RB Leipzig 3-0 on Tuesday.
"Paris are a great team, they fought their way into the semi-final and then reached the final. We will analyse some things, we know they have quick players," added Flick, whose free-scoring Bayern have netted 42 goals in the competition this season – only the 1999-00 Barcelona (45) team have managed more in a single campaign.
"We will look to organise our defence, but we know our biggest strength is putting our opponents under pressure.
"Thomas is doing a sensational job, that is excellent. I visited him once and I have the opinion that his team is working very well. I'm looking forward to Sunday."
Asked about Lewandowski's opportunity to break Cristiano Ronaldo's Champions League scoring record on Sunday, Flick stressed his star striker won't be distracted by such an individual milestone.
"He won't think about that, he's happy that he finished our game. He works a lot for the team, that's very important," Flick said.