PSG had won the first leg 4-0, but the Blaugrana managed to turn the tie around and win 6-1 to qualify for the Champions League quarter-finals with a stunning result.
"I'm calm and chilled, as this [PSG] are a different team," Pochettino told the press prior the match against the Catalan side. "What happened can't be erased, but we want to build another future.
"And all of us always [want] to build something better than what happened."
"It is true that it is a special match," added Pochettino. "When you sign with PSG you feel that this date is going to be important and you can see the excitement at the club.
"It is obvious that PSG's goal is to win the Champions League."
"It always takes time for a team to function with a new coach," noted Pochettino.
"It is clear that over time they have constantly evolved beyond this new reality. Koeman has had time and Barcelona are much more solid.
"We are going to compete against a Barcelona [side] that also aspire to [win] the Champions League. I looked up to Koeman as a player and [I do it] now as a coach [too]."