United are three points ahead of PSG at the top of their group, having won in the Parc des Princes in their first game earlier this season.
"During our match at the Parc des Princes, we had performed well, but, given the evolution of this group H, I am sure that the Parisians will come to Old Trafford to win.
"We know how dangerous they can be."
This season, Mata has managed seven appearances for United, including starting for the Champions League defeat at Istanbul Basaksehir.
PSG go to Old Trafford needing victory to keep their hopes of qualifying from their Champions League group on track. PSG have traveled to England sitting in second place in Group H three points behind United. The French giants are ahead of third place Red Bull Leipzig courtesy of goal difference.
On former United teammate Ander Herrera, Mata added: "We exchange a lot, but our relationship goes beyond this kind of consideration. With Ander, we appreciate each other since our first meeting, with the Spanish U21s (in 2009). He's a good person, with whom I shared precious moments when he played for Manchester United (2014-2019).
"I saw him again after the game at the Parc (on October 20), we had a nice discussion in the tunnel."
- updated December 2