The Argentina midfielder is being linked with Manchester United this week.
However, after PSG's 4-0 rout of St Etienne, Tuchel said of goalscorer Paredes: "He always scores in training, it was necessary that he now scores in matches! It is deserved because he took his chance, to show his qualities and he is a player who can play for us.
"He's impressive because he gave a lot of quality and intensity to our game. He wins a lot of second balls for us, he works a lot defensively and he has quality with the ball, that's clear.
"Now he's in good shape, with good physical capacity. I am very happy for him that he has the ability to show his qualities. We could see on television that everyone was happy for him because he had this opportunity to score."