Mourinho was still in charge at Old Trafford when the draw was made pitting PSG against United in the last 16 of the Champions League, with the tie to be played across February and March.
Ole Gunnar Solskjaer was the Portuguese's replacement on a caretaker basis and he has made a stunning impact with United winning all six matches under his stewardship.
And Solskjaer's impact has not gone unnoticed in the French capital.
Choupo-Moting told RMC: "Manchester United, they have changed. But it's always like that when you change coaches.
"There may be a new state of mind in the team, everyone wants to show their best.
"But I do not care about other teams, we have to think about ourselves, we believe in ourselves.
"We have the quality to beat anyone but it will be a tough match because Manchester United are a very good team with great quality players."
PSG are currently enjoying another standout campaign in France.
They are yet to suffer a single defeat through 18 fixtures in the defence of their Ligue 1 title.
Just four points have been dropped so far, with Thomas Tuchel's side proving once again that they remain a dominant force in domestic football.
They were not entirely convincing, though, in securing Champions League progress from Group C, and that will have offered hope to United as they ready themselves for a heavyweight European encounter.